Wilted, downward-hanging foliage is often the first obvious symptom of Armillaria root rot. Other symptoms include foliage yellowing, leaf drop, and dieback of upper limbs. During the rainy fall and winter, groups of short-lived mushrooms often grow around the base of Armillaria-infected trees.

Signs of damage

Cultural practices can also be effective for preventing the spread of Armillaria. High temperatures interfere with the progression of this disease; if soil temperatures reach 79 °F (26 °C), then the growth of Armillaria in the soil will be limited. Using collar excavation to expose primary roots directly below the crown to the continuous cycle of solar heating and air may reduce the colonization from Armillaria in trees that are already infected. This is called root collar excavation (RCE), and while it has been applied to citrus orchards and grapevines, this method has high labor costs and involvement due to the difficulty of carefully exposing these primary roots.

How to prevent

Sadly, there is no absolute treatment for Armillaria root rot. The disease can be managed by the consistent removal of dead trees and infected stumps. Armillaria requires consistent moisture to survive, and in citrus groves, excavation around the root crown has been an effective deterrent but not an ultimate cure.

Treat

main

description

description_sm

description_sm_2

Armillaria root rot

Changes in leaf color or texture can signal an insect problem. Leaves may become spotted, speckled or yellowed when insects are present. Leaves might also become distorted or misshapen, often looking cupped or pinched. You may spot webbing draped along leaf undersides or where leaves attach to stems.

Remove any sources of food, water or shelter. Store items in safe and enclosed containers. Dispose of garbage regularly with a tightly closed lid. Reduce clutter or areas where pests can hide. Seal and close off any cracks or holes to eliminate outside entry.

Wash plants with a strong spray of water to dislodge aphids, or remove and destroy affected plant parts. Organic solutions include spraying with horticultural oil (petroleum- or vegetable-based oil used to smother insects), insecticidal soap or neem (insecticide made from a tropical tree by the same name).

Insecta

The symptoms in the upper parts of the plants cannot be recognized in early stages of root infection.

Diagnosis of this disease is difficult and laborious because infected roots in the soil can only be detected by digging up the soil and observing the roots by eye, trapping mycelia around the infected roots by the bait twig method

Sordariomycetes

If the stem is mushy or brittle, check the roots for the same conditions. The roots, too, should be pliable but firm. If both the stems and roots are brittle or mushy, the plant is dead and you will simply need to start over.

Repot your plant. Use a high-quality indoor plant potting mix to revitalise your plant, and choose a pot that's wider than the last one. ... Trim your plant. If there's damage to the roots, trim back the leaves. Move your plant.  Water your plant.  Feed your plant.  Wipe your plant.

Gently remove the plant from its container. If you see more roots than soil, or roots coiling around the inside of the pot, it is time for a bigger container. Over time, most plants outgrow their pots. Sometimes, all it takes to revive a dying plant is a little repotting.

Dead plant

Symptoms of Tobacco Rattle Virus vary based on the plant host, which differs widely in this disease. Common symptoms include mottling, cholortic or necrotic local lesion, ringspots or line patterns, and systemic necrosis.

Abandon fields highly infested with TRV.  Avoid planting TRV-sensitive cultivars. Use virus-free seed. Practice crop rotation using TRV non-host crop alfalfa Control weeds to lower the viruliferous stubby root nematode numbers.

Once plants have become infected with TRV, they remain infected indefinitely. Infected plant cannot be treated in any way to eliminate the virus and should be removed and disposed of by burning, burying or composting.

Tobacco rattle virus

Fungus gnat damage will appear similar to that of any other root-related issue, such as root rot. Lower leaves may turn yellow and drop, and the plant’s growth may slow down or stop completely. In particularly bad cases, wilting of the entire plant could occur, followed by the death of the plant if roots are extremely damaged. 
In small numbers, fungus gnats are more of an annoyance than anything. In fact, the adult gnats don’t actively harm plants nor people. If their population gets out of hand, however, the larvae may start feeding on plant roots, causing notable damage. This is especially bad for young plants, such as seedlings, which have only a few delicate roots. Fungus gnats are also capable of spreading the plant pathogen that causes damping off and the eventual death of seedlings.

1. Keep soil dry: Fungus gnats seek out moist soil, so allowing your houseplants to dry out a bit between waterings can slow down or stop an infestation. Let the top inch or two of soil dry out before watering again, and try to go as long as possible between waterings. Gnats may be deterred from laying their eggs if the soil is dry on the surface.
2. Mosquito dunks (with beneficial bacteria): Mosquito dunks are used to keep mosquito larvae from populating fountains, animal troughs, fish ponds, and other small bodies of water. The product consists of a dry pellet containing a type of bacteria called Bacillus thuringiensis subspecies isrealensis. This beneficial bacteria infects and kills the larvae of flying insects, including mosquitoes, fruit flies, and fungus gnats.
To use mosquito dunks: Fill up a gallon jug (or watering can) with clean water and toss in a mosquito dunk. It’s a good idea to break up the dunk a bit before placing it in the water, or you can wait for it to soften before breaking it apart. Let the dunk soak in the water for as long as possible (at least overnight), then remove it from the water (the dunk can be reused) and use this water for fungus gnat–infested plants. The bacteria will have leeched into the water and will now infect and kill any larvae that come into contact with it in the soil. Repeat this process every time you water your plants for at least a few months.
3. Cover drainage holes: Though gnats typically remain near the tops of pots, they may find their way to the drainage holes on the underside of a pot and start laying eggs there, too. If this happens, cover the drainage holes with a piece of synthetic fabric to prevent the gnats from getting in or out of the hole, but to also let water pass through freely. Attach with tape or rubber bands.

Getting rid of fungus gnats is all about consistency. Catching the adults is fairly easy, but because the adult population comes in cycles, you need to make sure that your traps are refreshed regularly. For the best results, use a combination of the traps :
1. Sticky cards traps: These traps consist of a yellow note card covered in a sticky adhesive. They are most effective when cut into small squares and placed directly on top of the soil or attached to skewers just above the soil. Adult gnats will fly or crawl onto the card and become trapped. Fungus gnats are attracted to the color yellow, so use the yellow sticky cards rather than the blue ones. 
2. Cider-vinegar traps: Simple and effective, cider-vinegar traps consist of a shallow container with a small amount of apple cider vinegar, water, and liquid dish soap.
To make a cider-vinegar trap: Find a shallow container—a tuna can is perfect—and fill it with equal parts water and apple cider vinegar. (The liquid should be at least ¼-inch deep.) Put a few drops of liquid dish soap into the mixture and stir gently. Place the trap near the base of the affected plant or, ideally, inside the pot on top of the soil. Check it every few days to refresh with new vinegar and water.
3.Flypaper: Flypaper ribbons, such as those hung in horse barns to catch outdoor flies, can also be used to catch fungus gnats. However, these traps are usually overkill for gnats and can easily get stuck to things you don’t want them to stick to, such as furniture, hair, plants, and so on.

Fungus Gnats

A range of lesions can occur including concentric oblong light oval-shaped rings (early sign), light green diamond-shaped areas, concentric green and tan oval-shaped rings, tan necrotic spots, and green islands within tan necrotic spots. Damage can reduce harvest yield and grade of onions.

Reduced bulb size and quality of symptoms develop while bulbs are still growing. Control thrips. Control weeds and volunteer onion plants. Remove and destroy infected plants.

Monitor thrips populations with sticky traps starting in June. Damage is often first noticed at field edges, in areas of stressed plants, or in locations with thin plant stands. Infected plants may not show symptoms for several weeks. Sometimes symptoms may never appear. Reduced bulb size and quality of symptoms develop while bulbs are still growing. Control thrips. Control weeds and volunteer onion plants. Remove and destroy infected plants. Rotate crops.

Iris yellow spot virus

Rust symptoms first appear on the upper and/or lower surfaces of leaves as small yellow or white slightly raised spots.

Remove all infected parts and destroy them. For bramble fruits, remove and destroy all the infected plants and replant the area with resistant varieties. Clean away all debris in between plants to prevent rust from spreading. Avoid splashing water onto the leaves, as this can help spread rust.

Use a mild bleach solution, and rinse and dry them thoroughly before putting them away. Rake up and remove fallen or dead leaves and other plant debris. Some gardeners compost vegetation that show signs of rust, expecting the compost pile to heat up enough to kill the spores.

Rust

Southern blight on plants is most likely to occur in the summer months when the soil is warm and moist. Symptoms include discolored lower leaves, wilted foliage, and plant collapse and it usually results in the death of the plant.

Preventing entry of the pathogen. Use of healthy, certified seeds of known origin. Careful cleaning of agricultural tools. Avoiding environmental conditions that favour development of the pathogen. Irrigation management. Plant density and growth habitats.

Soil solarization and certain organic amendments (e.g. composted chicken manure and rye-vetch green manure), as well as introducing certain Trichoderma spp. have also been shown to reduce plant death and number of sclerotia produced in the field in tomatoes. In addition to these cultural methods, chemical methods (e.g. fungicides) can also be employed.These methods all disrupt the production of mycelium and sclerotia, thus reducing the spread of disease.

Southern blight

Browning of leaf margins and/or yellowing or darkening of the areas between the main leaf veins are symptoms of leaf scorch. Due to environmental causes, leaves may dry, turn brown, and become brittle. Look for damage to trees and shrubs on the upper portion on the sunny, southern side and on the windy side. Premature dropping of leaves and twig dieback may occur during the late summer. Symptoms usually appear after drying winds in conjunction with periods of hot, dry weather. Leaf scorch on narrow leaf evergreens appears as brown or purple brown discoloration of the needle tips. If unfavorable conditions become more severe, browning of needles increases. This should not be confused with the browning and shedding of older interior needles. Scorch may result from hot, dry weather in summer or from strong, dry winter winds when the ground is frozen. Symptoms may not become apparent for a month or more after the initial injury. Winter leaf scorch in evergreen plants usually appears as two long, brown areas paralleling the main leaf vein.

1. Plant Thoughtfully. Even your plants that love to soak up the sun need some form of shade to protect them.
2. Use Sunblock. If you can't provide your plants the amount of shade they need, use another method to keep them insulated and keep moisture in the soil around them.
3. Create Shade.

1. Water when needed and maintain plant vigor. Plant in a fertile, well-drained soil at the same depth the plants grew in at the nursery and with an adequate supply of organic matter. Soil should be moist to a depth of 10 to 12 inches after a thorough watering. This should be done about once weekly. It is very important for the trees, especially broadleaf and needled evergreens, to be well watered going into the winter period. Water during this period if seasonal rains are not adequate or during the winter when the soil is not frozen. Annuals and perennials require more frequent watering than most trees and shrubs. 
2. Fertilize. Fertilize plants in early spring based on a soil test and the directions printed on the fertilizer container. Nitrogen should be applied annually based on the area to be fertilized, the type of plant, and the diameter of the trunk. Do not fertilize with nitrogen in the late fall as it may cause new soft growth easily damaged by cold weather. 
3. Mulch. Organic mulches (pine needles, wood chips, composted leaves, pine bark, cypress mulch) can help retain moisture during the summer and fall droughts. In the winter this mulch prevents the alternate freezing and thawing of the soil. Mulch will also cool the soil in summer. 
4. Screens. Screens may be used to protect trees and plants in areas exposed to wind and sun, but it is best not to plant tender plants in these exposures. 
5. Exposure. Other factors which can result in scorch are excessive fertilizer, deicing salt, herbicide, dog urine, trash fires, leaking sewer or gas mains, girdling roots or strangling wires, vehicle exhaust, and heat reflected from buildings. Elimination of the exposure to these elements is the only correction. 
6. Physical hazards. Avoid root injury when digging near trees and shrubs. Care should be taken to not injure the bark and roots when using lawnmowers, weed whips, and edging tools.

Sunburn

The first sign of powdery mildew is pale yellow leaf spots. White powdery spots can form on both upper and lower leaf surfaces, and quickly expand into large blotches. The large blotches can cover entire leaf, petiole and stem surfaces. When powdery mildew infects the majority of the foliage, the plant weakens and the fruit ripens prematurely.

Control is possible with triadimefon and propiconazole. It is also possible with hexaconazole, myclobutanil, and penconazole.

Standard fungicides are an effective way to manage powdery mildew disease on plants. Spray programs of conventional fungicides are advised to begin when powdery mildew symptoms and signs are first noticed. Conventional fungicides should be applied on a regular basis for best results against the disease.

Powdery mildew

Plants with severe rust infection may appear stunted, chlorotic (yellowed), or may display signs of infection such as rust fruiting bodies. Rust fungi grow intracellularly, and make spore-producing fruiting bodies within or, more often, on the surfaces of affected plant parts.

Pick off and destroy infected leaves and frequently rake under plants to remove all fallen debris. Water in the early morning hours — avoiding overhead sprinklers — to give plants time to dry out during the day.

Select rust-resistant plant varieties when available.

Pucciniaceae

Phyllosticta causes circular leaf spots with brown/reddish borders. The spots can be really large covering a large area of the leaf. Initial symptoms include small watersoaked regions on the leaves. lesions become more apparent with a ring-like pattern at alter stages.

Repeated applications of fungicides such as Dithane M45, Captan, Ferbam, Mancozeb or thiophanate-methylbased treatments will help control infection levels and can prevent new infections in healthy plants, but it is difficult if not impossible to completely eradicate the fungus in an infected host plant.

Remove and dispose of affected leaves from infected plants to keep the fungal spores from spreading into the growing environment. Some growers have reported covering the mature lesions with clear nail polish to prevent the dissemination of spores.

Phyllosticta leaf spots

The leaves become narrower and longer, and with severe damage, the plants become chlorotic and die.

There is no cure for nectria canker, so it is important to take steps to prevent it affecting young and vulnerable trees. Pruning injuries can be a major source of infection, so avoid pruning trees in the fall, especially in wet conditions. Restrict pruning to dry weather and remove any branches or stems that have been infected with the fungus.

Freezing damage is another important way in which trees get infected. For young transplants, providing protection from freezing can prevent the disease. Avoid other types of injury and keep your trees healthy to minimize the risks from nectria infection. This means being careful with the lawnmower around trees, preventing or managing pests, and providing adequate water and nutrients.

Nectriaceae

Initial symptoms include large, angular or blocky, yellow areas visible on the upper surface. As lesions mature, they expand rapidly and turn brown. The under surface of infected leaves appears watersoaked. Upon closer inspection, a purple-brown mold (see arrow) becomes apparent. Small spores shaped like footballs can be observed among the mold with a 10x hand lens. In disease-favorable conditions (cool nights with long dew periods), downy mildew will spread rapidly, destroying leaf tissue without affecting stems or petioles.

As downy mildew like moist conditions, avoid dense planting and control weeds, to provide good air circulation around the plants. Water plants early in the morning, like watering plants in the evening, leads to high humidity that persists throughout the night.

Because the downy mildew pathogen does not overwinter in midwestern fields, crop rotations and tillage practices do not affect disease development. The pathogen tends to become established in late summer. Therefore, planting early season varieties may further reduce the already minor threat posed by downy mildew. Fungicides applied specifically for downy mildew control may be unnecessary. Broad spectrum protectant fungicides such as chlorothalonil, mancozeb, and fixed copper are at least somewhat effective in protecting against downy mildew infection. Systemic fungicides are labeled for use against cucurbit downy mildew, but are recommended only after diagnosis of this disease has been confirmed. One way to control downy mildew is to eliminate moisture and humidity around the impacted plants. Watering from below, such as with a drip system, and improve air circulation through selective pruning. In enclosed environments, like in the house or in a greenhouse, reducing the humidity will help as well.

Downy mildew

Ascomycetes are characterized by septate hyphae with simple pores. Asexual reproduction by conidia. Sexual reproduction by ascospores, typically eight, in an ascus. Asci are often housed in a fruiting body or ascocarp e.g. cleistothecia or perithecia.

Good gardening habits and effective treatment help prevent, stop and control fungal disease: 

1. Start by planting healthy stock. ...
2. Choose planting sites based on plant needs. ...
3. Avoid overhead watering. ...
4. Water early in the day. ...
5. Don't crowd plants. ...
6. Don't work a wet garden. ...
7. Treat with a trusted, proven fungicide.

To control fungal outbreaks, as with bacteria, remove all infected plant parts, or plants. You may also choose to apply a fungicide. There are many products available for treatment, organically (copper, sulfur, and baking soda are common) or synthetically.

Ascomycetes

Raised yellowish-orange, powdery pustules on the surface of infected foliage. Significant foliar dieback occurs on especially susceptible cultivars.

As with other fungus, daylily rust thrives in moisture. Use soaker hoses rather than overhead watering systems and water in the morning rather than late in the day or at night. This will cut down on the amount of time that the leaves remain wet.

Do not move or transport infected plant material. Carefully inspect incoming plant material for signs of rust. Fungicide applications are needed for disease management, especially on susceptible cultivars. Contact your local extension office for information on ratings of cultivar susceptibility and current fungicide control recommendations.

Daylily rust

Brown, yellow, gray, or straw-colored needles at tip of current season's growth; needles usually stunted and shoot may curl. Branch dieback. Small, black fruiting bodies on needles, cones, or shoot tissue. Cankers on stems or branches. Oozing resin that adheres to blighted needles.

Preventing the initial infection is a better strategy than attempting to cure a diseased tree. The first line of defense in preventing disease is planting disease free stock, planting in a disease free area, and selecting a disease resistant species. Beyond the selection of clean, resistant stock and planting location, trees that have proper water and nutrient management are healthier and less susceptible to Diplodia tip blight. Controlling wood boring insects that create wounds for Diplodia to exploit, is another cultural practice that can prevent disease. Poor airflow and high humidity are conditions that favor disease development; keeping grass and weeds trimmed down at the base of the tree allows for better airflow and can limit disease development. Once a tree is diseased, the goal is to limit the amount of inoculum present. The blighted needles and cones will have the pycnidia survival structures that contain thousands of spores. Remove debris from the base of the tree and destroy. During dry weather (not during Spring or early Summer), cut away infected shoots, cones, and branches. Sanitary techniques like sanitizing pruning tools between each cut will prevent further spread of the disease.

When disease pressure is high, chemical controls is advised. First, spray should occur early spring at candle elongation. Repeated sprays should occur every two weeks until needles reach full size. Fungicides containing the following active ingredients have been shown to be efficacious: chlorothalonil, methyl, thiophanate-methyl, mancozeb, and copper hydroxide with mancozeb. Always read and follow the label.

Sphaeropsis blight

Usually the first sign of thrip damage is faded or dirty looking leaves. The leaves will start by turning white or grayish in color, then eventually brown as the damaged areas start to die.
Though it’s possible for thrips to kill a houseplant, it’s rare. Mature, healthy houseplants can handle a pretty heavy infestation. The biggest threat is to small or weak houseplants.
However, not only is a thrip infestation gross, they make your indoor plants look terrible, and heavy damage can stunt their growth. Other common symptoms include:
- Brown stripes on the leaves
- Faded, splotchy, pale-colored leaves
- Parts of the leaves are dying
- Flower buds are malformed, dropping, or won’t open
- Leaves start dropping unexpectedly
- New growth is deformed

Thrips can be difficult to get rid of. So, once you finally win the battle, you want to prevent them from ever coming back!
The good news is that there are a few easy ways to prevent thrips from infesting your houseplants…
- Monitor them on a regular basis for the first signs of an infestation
- Debug all of your plants before bringing them back inside for the winter
- Keep anything that you bring in from your garden (cut flowers, veggies…etc) far away from your houseplants
- Inspect all new houseplants before bringing them home, then quarantine them for a few weeks afterward

The first thing you should do as soon as you spot thrips on a houseplant is to quarantine the infested plant immediately. Then check all of the surrounding houseplants for signs of thrips, and isolate any others you may find.Make sure that you begin treating the infestation right away. Also, to help prevent thrips from spreading, always wash your hands after handling an infested houseplant.
RINSE THE LEAVES
If you can, take your houseplant outside, and rinse the leaves with the hose. That will remove many of the bugs, and quickly knock down their population.You could rinse the leaves in the sink or shower instead, and that will work too. Be sure to use tepid water, and take care not to overwater your houseplant in the process.
INSECTICIDAL SOAP
Soap kills thrips on contact, and will help to give you the upper hand. You can use a pre-mixed organic insecticidal soap, or make your own using 1 tsp mild liquid soap to 1 liter of water.Be sure to spray it directly on the infested leaves to kill the bugs. Insecticidal soap doesn’t have any kind of residual effect, so it’s important to treat them often in order to completely get rid of thrips.
WASH YOUR HOUSEPLANT
You could also try washing the leaves with diluted mild liquid soap, and rinse it off with water. This will kill thrips as well, and help to quickly get the population under control.Make sure you wash the undersides of leaves too, that’s where thrips like to hide. But before washing all of the leaves, it’s best to test the soap on a few first, to make sure it doesn’t damage your houseplant.
NEEM OIL 
It’s a naturally occurring insecticide, and also has a residual effect that will help to deter future infestations.Spray a neem oil solution directly on the leaves and stems. This will kill some of the bugs on contact, and others will die when they feed on the neem oil covered leaves. Either a pre-mixed horticultural oil or a hot pepper wax spray can also be very effective to get rid of thrips on houseplants.
STICKY TRAPS 
Since adult thrips are able to fly, sticky traps can work very well to capture them. Place either yellow or blue sticky traps near the infested houseplant to attract them.

Houseplant Thrips

Initially spots of limited size, slightly concave, appear at the peduncular scar of some fruits, or near growth cracks or various wounds. They gradually spread with a fairly typical dark brown to black colour. The lesions decay further while their perimeter is clearly identified. They eventually cover a large proportion of ripe or unripe fruits if the environmental conditions are favourable. Whatever their development stage, the fruits undergo internal rot extending to the seeds. Brown to black globular structures, pycnidia, can be observed in the damaged tissues. They are spherical and irregularly shaped, ostiolate, and contain many hyaline and unicellular conidia, containing two lipid droplets.

Dothideomycetes

Flowers or leaves may develop silvery streaks. Heavily infested leaves appear brownish or silvery, and growing points may become contorted. Some species of thrips leave sooty spots of black fecal matter on the leaves. Thrips also vector plant diseases.

The main measures you can apply to control this pest are primarily a matter of proper maintenance of the garden. Here’s what you can do to keep away the plants in your garden from a thrip infestation: take care of your garden soil, water it regularly and apply mulch on it. It is known that thrips are attracted to plants that are already ill or unhealthy and thus, they can often be seen on plants growing in harsh conditions, such as in dry land, not irrigated and without mulch on it;
eliminate all vegetal residues, such as dry or wilted flowers;
do not fertilize the soil more than necessary, as this will encourage the growth of other juicy plants, that will attract other pests, such as aphides;
cultivate plants that are adapted to the environment from the area; if you cultivate plants that prefer sun, in a shady and chilly area, they will become more predisposed to thrip infestation.
be vigilant and periodically inspect the plants to see if they have or have not been infested. You can see signs of thrips infestation in the inferior sides of the leaves and in the nip between the leaves and stems. Do not hesitate to remove the already infested plants and to cut the grass and weeds around your home to exclude alternative hosts where thrips could relocate.
do not cut the leaves off of the plants that thrips prefer with a scissor, as this will determine a younger and softer leaf to grow, thus pleasing these pests;
inspecting all the plants you buy before you bring and plant them into your garden;
provide good, constant irrigation to plants;
using row covers, hot caps, or other kinds of cages with a fine mesh in order to keep thrips (and other insects) away from vulnerable vegetables or young plants; once the latter become larger, though, it is important to remove the covers, allowing them enough growing space.

When controlling thrips, you can prune and get rid of any injured areas on the plant. Regular pruning helps get rid of thrips. Thrips on flowers can be eliminated as soon as you see signs of damage by using a mild insecticide like insecticidal soap or neem oil, or by pruning the flowers.

Thysanoptera

Leaves Go Yellow and Fall Off. Dropping Old and New Leaves Alike.  Wilting, Limp Leaves. Leaves Turning Splotchy Black or Dark Brown.  Mushy Roots Mean Overwatering.  An Overwatered Succulent Will Rot and Turn Mushy.

Soaking the ground for a longer period of time less often, and not watering by hand but using a sprinkler or soaker hose, is the way to handle that situation. Mulch around the plant will also help keep a more even level of moisture.

Move your plant to a shady area even if it is a full-sun plant. Remove any dead or dying leaves. These should be easily recognizable. Check your pot for proper drainage and, if possible, create additional air space around the roots. This will allow oxygen to reach the root zone. Remove any dead or dying roots and keep only the roots that are healthy. Water only when the soil is dry to the touch, but do not let it get too dry. You should also seize all fertilization at this point until the plant is healthy again. Treat with a fungicide.

Water excess and/or uneven watering

Tan to brown leaf spots, small black fruiting bodies (pycnidia) may be visible in the lesions. Lesions on Rudbeckia and Echinacea are purple. Lesions may be more severe on older foliage.

Avoid overhead irrigation or carefully time it such that the duration of leaf wetness is minimized.

Protectant fungicides can be used to manage Septoria leaf spot.

Mycosphaerellaceae

A diagnostic feature of this disease is the presence of many dark-brown, pimple-like structures called pycnidia (fruiting bodies of the fungus) that are readily visible in the tan centers of the spots. When spots are numerous, affected leaves turn yellow and eventually shrivel up, brown, and drop off.

Use disease-free seed. There's no evidence that this fungus is carried by seeds, but err on the safe side and don't save seed from infected plants. Thoroughly processing the tomato seeds you are saving will also help rid the seeds of lingering diseases.
Start with a clean garden. Dispose of all affected plants. The fungus can over-winter on the debris of diseased plants. It's important to dispose of all the affected plants far away from the garden and the compost pile. Keep in mind that it may have spread to your potatoes and eggplants, too.
Avoid overhead watering. Water aids the spread of Septoria leaf spot. Keep it off the leaves as much as possible by watering at the base of the plant only. Of course, it's impossible to keep the rain off your plants, but every little bit helps.
Provide room for air circulation. Leave some space between your tomato plants so there is good airflow. Stake them so that they are not touching the ground and not all bunched together. Good air circulation is especially important during damp and rainy periods.
Mulch below the plants. A layer of mulch will help prevent spores on the ground from splashing up onto the lower leaves.
Plant next year's tomatoes in a different section of your garden. In small gardens, it's not always practical to rotate your crops, so good clean up and sanitation become even more important.

Removing infected leaves. Remove infected leaves immediately, and be sure to wash your hands and pruners thoroughly before working with uninfected plants.
Consider organic fungicide options. Fungicides containing either copper or potassium bicarbonate will help prevent the spreading of the disease. Begin spraying as soon as the first symptoms appear and follow the label directions for continued management.
Consider chemical fungicides. While chemical options are not ideal, they may be the only option for controlling advanced infections. One of the least toxic and most effective is chlorothalonil (sold under the names Fungonil and Daconil).

Septoria leaf spot

Symptoms of infected plants are premature yellowing, dieback, wilting of older leaves, and stunting of plants, followed by death of all foliage and sometimes root rot. Unlike Botrytis species, S. cepivorum does not produce spores to spread and establish disease.

The hyperparasite Coniothyrium minitans may provide biological control, and a commercialized product ‘Contans’ is based on this.

Certain crops such as lettuce, beans and chicory can contribute to inoculum build-up significantly. Soil infestations can also be reduced by metam sodium and biological soil disinfestation.

Sclerotiniaceae

Typical leaf symptoms of viral diseases include mosaic patterns, chlorotic or necrotic lesions (Figure 13), yellowing, stripes or streaks, vein clearing, vein banding, and leaf rolling and curling.

Remove all infected plants and destroy them. Do NOT put them in the compost pile, as the virus may persist in infected plant matter. Burn infected plants or throw them out with the garbage. Monitor the rest of your plants closely, especially those that were located near infected plants. Disinfect gardening tools after every use. Keep a bottle of a weak bleach solution or other antiviral disinfectant to wipe your tools down with.

1. Remove all infected plants and destroy them. Do NOT put them in the compost pile, as the virus may persist in infected plant matter.
2. Monitor the rest of your plants closely, especially those that were located near infected plants.
3. Disinfect gardening tools after every use.

Viruses

General symptoms on the solanaceous crops and cucurbits include seed rot and seedling blight which discolors the roots and causes seedlings to topple over. Preemergence and postemergence damping-off are also possible symptoms that may occur.

Avoid overhead watering that can produce surface runoff, and consider slow drip irrigation instead. Hardy Phytophthora blight pathogens will survive in both hot summer and cold winter compost piles. Remove infected plants immediately, bag and dispose of infected debris, and always keep your garden clean.

Crop rotation may reduce the number of pathogens in the soil and, "a minimum of a 3 years crop rotation which alternates with non-host species is recommended to avoid build-up of P. capsici spores." Crops should also avoid conditions that would be conducive to the pathogen by using well drained soils and raised beds. As stated above, "Excess moisture is the single most important component to the initial infection and subsequent spreading of Phytophthora capsici. Overall, a study by K.H. Lamour and M.K. Hausbeck found that "crop rotation and mefenoxam are not likely to provide economic control". Mefenoxem is the active enantiomer contained in the racemic fungicide metalaxyl used to defend against Phytophthora capsici. Sexual recombination provides the genetic diversity to promote resistance towards fungicides in P. capsici. The failure of crop rotation as a means to control P. capsici may also be due to weeds playing the role of an alternative host in the absence of common hosts. According to a study done by the University of Florida, "In Florida, and perhaps elsewhere, weeds may contribute to pathogen survival in the absence of a host crop or when propagules may not readily survive in soil or plant debris." To avoid fruit rot of vegetable crops in the Cucurbitaceae, trellising cucurbit fruits and other ways to keep the fruit off the ground is a way to control secondary inoculants (zoospores) from physically being splashed from the soil onto the fruit. Control of Phytophthora capsici is easier in drier climates with less rainfall such as California. In these areas, it is important to practice placing drip irrigation emitters away from the stems of pepper plants in order to reduce the incidence of crown rot in peppers.

Phytophthora blight

Symptoms begin as oval to elongate lesions that are generally reddish-brown in color. In the late stages of the disease, erumpent pustules produce numerous black sooty spores. Severe infestations with many stem lesions may weaken plant stems and result in lodging.

Since the fungus overwinters on other plant material, clean up dead plants at the end of the season. Rotate your allium crops to areas that were not previously hosting plants in the family. Remove wild forms of allium, which can also host the fungal spores.

The rust species Puccinia obtegens has shown some promise for controlling Canada thistle, but it must be used in conjunction with other control measures to be effective.

Puccinia

Wilting. This is the classic sign of an under watered plant. Too little water causes a plant to lose turgor, the rigidity in cells and tissues. There are some diseases that can trigger wilting, but the easiest and most likely explanation is under watering. Dry soil. If the soil around a plant is dry, it may need more water. Exceptions to this are some succulents, like cacti, which don’t need much water because they can store it so well. Dry, dead leaf tips. When a plant doesn’t get enough water, the tips and edges of leaves dry out and turn brown. Ultimately, entire leaves will brown and die. Slow growth. If you are chronically under watering a plant, but still giving it enough water to survive, growth will be slower than normal or expected. New growth, such as leaves, may be small. Visible footprints. For a sign that turf grass is not getting adequate water, look to your footprints. After you step on the grass, it should bounce back quickly. If the footprints remain visible for several minutes, the grass is too dry.

Mulch plants with a 3-to-4-inch layer of organic mulch (woodchips, shredded bark) to reduce soil evaporation and temperature fluctuations, and to conserve moisture. Irrigate slowly so water percolates down into the soil. Do not fertilize unless adequate irrigation is available.

Most garden plants, flowers, and shrubs do best when they receive at least 1 inch of water per week, although they may need more during hot, dry spells. Rain isn't always sufficient at supplying enough water for plants to thrive, so don't count on it to keep plants healthy.

Water deficiency

Symptoms first appear as a slight yellowing of foliage and wilting of upper leaves. As wilting progresses, leaves may turn dull-green to brown and remain attached to the plant. When the stem and roots are cut diagonally, reddish-brown streaks are visible in the vascular tissues.
Signs and symptoms:
- Initially, plants wilt during the hottest part of the day and recover at night.
- Leaflets turn yellow on one side of the plant, or even just leaflets on one half of a compound leaf.
- The entire plant soon turns yellow and wilts. Browning of leaves occurs rarely.
- Peel the epidermis off the lower stem to see dark red and brown discolored vascular tissue.

Fusarium is most prevalent in warm soils. It is harbored in old plant debris and soil. The best way to prevent infection in your crops or plants is rotation and sterilization. 
Never plant the same crop in the same place annually. 
Pots should be sterilized with a bleach solution and new soil used when reusing them. You can also solarize beds, by spreading black plastic over an area in full sun for a month to kill the fungus. This causes extreme high temperatures that will “cook” the fungus and provide good control of Fusarium. 
Wash off tillage equipment, shoes and other tools that might have encountered infected soil. Remove all old plant debris annually and if you think it might be contaminated, burn it. Do not compost contaminated material as this provides an ideal incubation condition for propagating the fungus.

1 Plant resistant varieties when available.
2 Remove stricken growth from the garden and sterilize pruning clippers (one part bleach to 4 parts water) between cuts.
3 Use fumigants to control many garden insects, like cucumber beetles, which are known to spread the disease.
4 High nitrogen fertilizers may increase susceptibility to the disease. Test your soil and use a slow-release, organic fertilizer in the vegetable garden.
5 Hand pull or spot treat weeds using a weed flamer or natural herbicide — many weed species host the disease pathogen.
6 Mycostop is a biological fungicide that will safely protect crops against wilt caused by Fusarium. Approved for use in organic crop production, it can be applied as a soil spray or drench (1-2 gm/ 100 sq ft) to seedlings, ornamentals and vegetables. Apply sufficient water during application to move Mycostop into the root zone.
7 If the disease persists, it is best to remove the entire plant and solarize the soil before planting again.
To solarize the soil, you must leave a clear plastic tarp on the soil surface for 4-6 weeks during the hottest part of the year. Soil solarization will reduce or eliminate many soil inhabiting pests including nematodes, fungi, insects, weeds and weed seeds.

Fusarium Wilt

Spider mites damage foliage by sucking juices from the leaves. This shows up as stippling on the leaves and more severe damage can result in leaf bronzing that may lead to leaf drop. Leaf drop increases incidence of sun/light burn and negatively affects both vegetative and flowering stages. 
Additional signs of spider mites are curled and/or burned leaf edges as well as leaves that have taken on a leathery texture. Webbing will be produced when mite populations grow in size and can be found on foliage, twigs and fruit/buds.

Look before you buy:
Inspect indoor and outdoor plants before purchasing to make sure they aren’t infested.
Keep plants healthy:
Make sure plants are well-watered and fertilized. Healthy plants are more able to withstand pests and diseases, while weakened or stressed plants are more susceptible to problems.
Keep the area clean:
Clear weeds and debris out of garden areas where pests can more easily hide.
Bump up moisture levels:
Since spider mites thrive in dry conditions, keep air humidity levels higher around plants.
Use high-quality soil:
Use a high-quality, sterile potting soil to avoid possible soil-borne pests.

Chemical pesticide use actually encourages the spread of spider mites by killing the beneficial insects that prey on them. Mites are also known to develop quick resistance to various pesticides. For these reasons, it’s important to control mites with effective natural and organic methods.
1 Prune leaves, stems and other infested parts of plants well past any webbing and discard in trash (and not in compost piles). Don’t be hesitant to pull entire plants to prevent the mites spreading to its neighbors.
2 Wash plants with a strong stream of water and reduce pest numbers.
3 Commercially available beneficial insects, such as ladybugs, lacewing and predatory mites are important natural enemies. For best results, make releases when pest levels are low to medium.
4 Nuke Em, a relatively new organic insecticide containing food-grade ingredients, works fast and kills most indoor gardening pests at the egg, larvae or adult stage. Best of all, it does this without leaving a residue on the leaves that can impact flavor.
5 BotaniGard ES is a highly effective biological insecticide containing Beauveria bassiana, an entomopathogenic fungus that attacks a long-list of troublesome crop pests – even resistant strains! Weekly applications can prevent insect population explosions and provide protection equal to or better than conventional chemical pesticides.
6 Mix Pure Neem Oil with Coco-Wet and apply every 3-5 days to kill pest eggs indoors and interrupt the reproductive cycle. Make sure to spray all plant parts, including the undersides of leaves. Do NOT apply when temperatures exceed 90˚F and wait at last six hours before turning lights on.
7 If populations are high, use a least-toxic, short-lived pesticide (Take Down Spray, Doktor Doom Foggers) to reduce infestations, then release predatory mites to maintain control.
8 Insecticidal soap or botanical insecticides can be used to spot treat heavily infested areas.
9 On fruit trees, horticultural oil should be applied early in the season or late in the fall to destroy overwintering eggs.
10 Dust on leaves, branches and fruit encourages mites. A mid-season hosing (or two!) to remove dust from trees is a worthwhile preventative.
11 Water stress makes both trees and garden plants more susceptible to mite infestations. Make sure your plants are properly watered.

Spider Mites

In the fruits, black or brown lesions (e.g., on pods, scab, and pitting) are common. Infection on the inflorescence produces blight, necrosis, and lesions with flecks and streaks. Infected leaves produce abnormal colors and patterns with dark, necrotic, angular, or irregular areas.

Plant resistant plants, or buy healthy transplants. Plant your plants in well-drained soil.  Water your plants with a drip sprinkler, as opposed to an overhead sprinkler.. Keep ripening fruits from touching the soil. Remember to rotate your plants every 2 to 3 years.

The best control products were Daconil Ultrex (chlorothalonil), Pageant (pyraclostrobin and boscalid) and Spectro 90WDG (chlorothalonil and thiophanate methyl). In addition, mancozeb (i.e., Dithane and Pentathlon) or copper were also very effective when used preventively.

Colletotrichum

Stems will be leggy or stretched out. Leaves turn yellow. Leaves are too small.

Arrange the light sources so that the plant receives the required number of photons.

Make sure your plant gets not too much/not too little light.

Light-related issue

Uneven swelling and maturation of the drupe, as well as premature staining without enlargement.

Neem oil as a preventative or light-infection treatment. Copper fungicides or phosphorus acid fungicides can treat larger scale infections. Prevention is the best cure.

Planting resistant cultivars. Treating with hot water on Roses cuttings can be effective, the water must be 44 degrees and treated for 15 minutes.

Peronosporaceae

Wilting, stunting, uneven plant growth, crown rot, plant death. Roots are discolored, the cortex may slough off, leaving the vascular cylinder.

Fertilize carefully with a slow-release formula in summer months. Water long and sparingly (no more than once a week), early in the day. This way, grass blades have a chance to dry out before nightfall. Aerate the soil to prevent thatch buildup and to loosen compacted, poorly draining soil.

For warm-season Pythium diseases, time fungicide applications preventively or at the very first onset of disease symptoms.

Pythium diseases

If your plant is not getting enough light, the most common sign is the yellowing and dropping of leaves, stunted leaf growth, elongated stems, and a dull-green color. If your plant is getting too much light, then its leaves will have singed tips, burned patches, or will be falling off (yikes!).

You can prevent this from happening by turning the plant once a week or every time you water. This ensure all leaves are exposed to roughly the same amount of light. All plants will bend towards their light source, and we recommend turning all your houseplants at least once a week to prevent “one-sided” growth.

Most plants will survive illuminance ten times lower than listed below but will not grow as well or bloom. Most plants grown as houseplants are selected because they are already adapted to growing at typical house temperatures, between 15° and 25°C. Exceptions do occur, and some plants require chilling periods at lower temperatures (down to 5° or 10°) in winter when less light is available. Houseplants are generally grown in specialized soils called potting compost or potting soil, not in local natural soil. A good potting compost mixture includes soil conditioners to provide the plant with nutrients, support, adequate drainage, and proper aeration. Most potting composts contain a combination of peat and vermiculite or perlite. Concern over environmental damage to peat bogs, however, is leading to the replacement of peat by coir (coconut fibre), which is a sustainable resource. Sterilised soil can also be used.

Lack of light

When late blight infects stems, everything above the infection site dies. Infected tomato fruits develop rough, leathery spots or dark, water-soaked areas that rot rapidly. Potato tubers bear dark, irregular spots on the surface and reddish-brown spots that extend down into the flesh. Decay continues after harvest.

Fungicides for the control of potato blight are normally only used in a preventative manner, optionally in conjunction with disease forecasting. In susceptible varieties, sometimes fungicide applications may be needed weekly. An early spray is most effective. The choice of fungicide can depend on the nature of local strains of P. infestans. Metalaxyl is a fungicide that was marketed for use against P. infestans, but suffered serious resistance issues when used on its own. In some regions of the world during the 1980s and 1990s, most strains of P. infestans became resistant to metalaxyl, but in subsequent years many populations shifted back to sensitivity. To reduce the occurrence of resistance, it is strongly advised to use single-target fungicides such as metalaxyl along with carbamate compounds. A combination of other compounds are recommended for managing metalaxyl-resistant strains. These include mandipropamid, chlorothalonil, fluazinam, triphenyltin, mancozeb, and others. In the United States, the Environmental Protection Agency has approved oxathiapiprolin for use against late blight.

Ridging is often used to reduce tuber contamination by blight. This normally involves piling soil or mulch around the stems of the potato blight meaning the pathogen has farther to travel to get to the tuber. Another approach is to destroy the canopy around five weeks before harvest, using a contact herbicide or sulfuric acid to burn off the foliage. Eliminating infected foliage reduces the likelihood of tuber infection.

Late blight

Plant stunting and severe curling of leaves occur when the leafhopper Empoasca fabae punctures the undersurfaces of leaves and veins of bush beans and inhibits growth. This leafhopper also feeds on alfalfa and causes leaves to turn yellow and drop off.

Try to avoid moisture or humidity relationships as they affect the habitats of homopterans.

Homoptera

The typical signs are brown or black feeding punctures visible on the affected plant tissues. Another conspicuous sign is honey dew, a sweet excretion that is released by the sucking insect. Often ants are attracted to feed on the honey dew.

Most true bugs do not cause serious harm to established plants. Provide proper cultural care so plants are vigorous. Provide adequate irrigation. Avoid growing shade-adapted species in full sunlight.

Effective ways to get rid of these stink bugs include sealing the house, dusting treatment, spraying with nicotine water, and using insect repellents. Stink bugs, also referred to as shield bugs, are a group of flying insects that belong to the Pentatomidae family of the order Hemiptera.

Hemiptera

Symptoms of bacterial infection in plants are much like the symptoms in fungal plant disease. They include leaf spots, blights, wilts, scabs, cankers and soft rots of roots, storage organs and fruit, and overgrowth. Bacterial spots: the most common symptom of bacterial disease is leaf spots.

The best way to prevent fungi from attacking your plants is to buy disease resistant varieties whenever possible. Other ways include minimizing the amount of water contacting foliage. Water at the soil level and early in the day. This allows foliage to dry out quickly, should it become wet.

Antibiotics: streptomycin and/or oxytetracycline may also help kill or suppress plant pathogenic bacteria prior to infection and reduce spread of the disease, but they will not cure plants that are already diseased. Antibiotics are also used to treat diseases caused by fastidious vascular bacteria.

Bacteria

The most common sign of anthracnose is the spots that appear on new leaves. These spots are irregularly shaped and are tan, brown, or black in color. In some trees, these spots appear all over the leaves and on others they may appear along the leaf veins.

Plant resistant plants, or buy healthy transplants. Plant your plants in well-drained soil.

Anthracnose diseases typically do not kill the host directly, however, repeated infections on woody plants over a period of years may lead to a general decline and dieback. Control of anthracnose diseases becomes important when the host is economically important and the goal is production for fruit or lumber. Otherwise, anthracnose diseases generally go unattended and raise concern only when premature leaf drop calls attention to the situation.

Anthracnose

Primary symptoms of infection include wilting leaves, blight of young shoots, sunken and darkened areas of stems with possible sap or resin flow, cankering on larger stems and branches, browning of the vascular tissue when bark is scraped away, and canopy dieback.

Avoid planting sites prone to spring frosts and use fertilization, irrigation, and weed control practices that discourage late-season growth and promote early hardening off. Sprays for mummy berry and botrytis may help, particularly during flowering.

Prune and discard all blighted stems and cankered branches from the canopy. For trees with thin bark and dense canopies (e.g. Japanese maple and kousa dogwood), annual sanitation pruning of dead stems, especially on interior canopy branches, can help to avoid disease outbreaks in the future.

Phomopsis cankers and blights

The earliest symptoms of rose rosette disease include a red pigmentation of the underside of leaf veins followed by sharply increased growth of vegetative shoots, which are typically more succulent than normal and colored in various shades of red. Leaves often become deformed, crinkled, and brittle with yellow mosaics and red pigmentation. As the disease progresses, leaves become very small, petioles are shortened, and most lateral buds grow, producing short, intensely red shoots. The disease causes the plant to be exceptionally susceptible to freeze damage. Symptoms on cultivated roses are typically less severe than on multiflora rose. Cultivated roses show symptoms of thickened, succulent stems and a proliferation of thorns. Symptoms can mimic some forms of herbicide damage.

Prune your roses in late winter or early spring. Do not use leaf blowers around your roses. Protect roses from prevailing winds with walls or other plants. Give your roses plenty of space. Control multiflora rose in your area.

1. Remove ornamental roses with symptoms. The entire plant including the roots should be removed and destroyed by burning or placing in a plastic bag. Care must be taken when working with diseased plants as you can facilitate spread of the mites that spreads the disease. Bag the plant before removal, cut it at ground level and then dig out the plant’s roots. Soil need not be removed. Clean tools and put on fresh clothing before moving to a disease-free plant or area. 2. Plant ornamental roses as far away as possible from known stands of multiflora rose. The general recommendation is maintain at least 300 feet between your roses and any stands of multiflora rose. Even greater distance is preferred especially if they are upwind of your desirable rose plants. 3. Control the disease by controlling the mite. Start mite control early by pruning your roses hard in late winter (back by 2/3) to remove as many overwintering mites as possible and then spray with horticultural oil to kill any remaining mites. Organic pesticides such as horticultural oils and insecticidal soap are recommended over other pesticides as these organic pesticides are less harmful to natural predators that feed on the problem mites. Apply weekly  during the months of June and July paying particular attention to the new growing tips where the mites will congregate. Refrain from using leaf blowers around roses as they can spread mites. 4. Help to isolate your roses. Do not plant roses too close together. With extra space between the plants mite movement can be reduced. Also, consider interplanting roses with other ornamental plants. 5. Using rose rosette disease as an IPM strategy. The multiflora rose is an exotic invasive species that is responsible for the degradation of millions of acres of farmland and recreational areas. Using the disease to control this invasive weed can cut costs and be considered environmentally friendly for reducing the amount of synthetic chemicals used. However, the disease also affects cultivated roses. One should be extremely cautious and good neighbor-minded when it comes to rose rosette disease.

Rose rosette disease

Tissues affected by the symptoms of Erwinia amylovora include blossoms, fruits, shoots, and branches of apple (Pomoideae), pear, and many other rosaceous plants. All symptoms are above ground and are typically easy to recognize. Symptoms on blossoms include water soaking of the floral receptacle, ovary, and peduncles. This results in a dull, gray-green appearance at 1–2 weeks after petal fall, and eventually tissues will shrivel and turn black. The base of the blossom and young fruit show similar symptoms as infection spreads. Opaque white- or amber-colored droplets of bacterial ooze can be seen on the infected tissue when the environment is high in humidity. Shoots show similar symptoms but develop much more rapidly. A “Shepherd's Crook” can be seen when the tip of the shoot wilts, and diseased shoot leaves typically have blackening along the mid-vein and then die. In number, diseased shoots give the tree a blighted appearance. Initial infection of blossoms and shoots can spread to larger tree limbs. Branches will darken and become water soaked. Advanced infection develops cracks in bark and a sunken surface. Wood under the bark will become streaked with black discoloration. Immature fruit forms water-soaked lesions and later turned black. Bacterial ooze can be found on these lesions. Severe infections result in fruit turning entirely black and shriveling.

Phytosanitary measures have been employed as the best sanitary measures against E. amylovora dispersal. High risk countries are encouraged not to import plants susceptible to the pathogen into their territory because, once the bacteria become established in an area it is nearly impossible to eradicate the disease. Nurseries and orchards in such regions are placed on strict phytosanitary surveillance measures and well-monitored. Imported and infected crops are destroyed as soon as they are noticed since the bacteria spreads very rapidly and eradication methods are usually costly and inefficient.

The only effective treatment for plants already infected is to prune off the affected branches and remove them from the area. Plants or trees should be inspected routinely for the appearance of new infections. The rest of the plant can be saved if the blighted wood is removed before the infection spreads to the roots. There is no known cure; prevention is the key.

Fire blight

Hosta virus X does not kill the plants infected, but Hostas that have been infected do show a variety of other symptoms, such as: Ink-bleed, which makes the plant look discolored in certain spots, and this effect is generally centered on a vein. An example of this is shown in the photo in this article. Desiccation or Collapsed tissue, which can be signs of heavier infection, makes the plant look as if it is dried out. Mottling, which makes the plant appear blotchy. This is not always a symptom of HVX, and could be from another virus, but it should always be treated as an infected plant regardless. A Hosta may no longer express symptoms of the virus when it grows back in the Spring, even though it may have shown symptoms in a previous year. Nonetheless, the plant should still be considered infected with HVX.

The only way to eliminate the disease is to destroy infected plants (and any associated plant debris) by burning (where allowed by local ordinance) or landfilling. DO NOT compost hostas with HVX.

Once a Hosta plant is infected, it will be infected for the rest of its life. Any plant suspected of being infected should be burned if it is legal to do so. If it is not, then it should be tossed in the garbage, but infected Hosta plants should never be composted. If any plant in a batch shows symptoms, the entire batch should be considered infected and be destroyed. Once a plant has been removed, the spot occupied by the Hosta should be left empty for a long time to prevent the spread of the virus to a plant that replaces it. The virus primarily spreads through infected sap, so cutting multiple plants with the same tool can spread the virus. Animals that eat the plants may also spread the virus through sap by eating from an infected plant and then eating from an uninfected plant.

Hosta virus x

Rhizoctonia solani can cause seed rot, root rot and lesions on hypocotyls. Damping-off occurs when germinating seedlings are infected prior to emergence. Reddish-brown, sunken lesions form on hypocotyls of young seedlings.

Planting seedlings in warmer soil and getting plants to emerge quickly helps minimize damage. Crop rotation also helps minimize the amount of inoculum that results in infection. A few resistant varieties with moderate resistance to Rhizoctonia can be used, but they produce lower yields and quantity than standard varieties. Minimizing soil compaction helps water infiltration, drainage, and aeration for the plants.

There is no cure for plants that already have damping off.

Rhizoctonia damping-off, blight and rot

Mealybugs damage crops in a variety of ways. Pupae and females drink the sap of the plant, slowing growth and causing deformation and yellowing of the leaves, sometimes with subsequent leaf fall. The overall effect is a weakening of photosynthesis and hence a decrease in yield.

To keep mealybugs at bay, spray your plants once a week with a solution of neem oil in water. If you coat all plant surfaces, the neem oil will slow or stop feeding on your plants by a wide variety of pests. In addition, the oil coats any eggs or crawlers and will smother them.

Pyrethroids such as permethrin, bifenthrin or cyfluthrin can be used to control mealybugs. Some gardeners use Green Lacewing (Chrysopidae) larvae to control mealybug infestations, as the larval Lacewings are voracious predators of aphids and other small insects.

Pseudococcidae

All members of the class produce basidiocarps which range in size from tiny cups a few millimeters across to a giant polypore (Phellinus ellipsoideus) greater than several meters across and weigh up to 500 kilograms (1,100 lb). Agaricomycetes produce mushrooms, and are therefore the most familiar and conspicuous of all Fungi. Other Fungi produce macroscopic fruiting bodies as well, but the diversity of forms in the Agaricomycetes is unmatched.

A proven fungicide that prevents disease from becoming active and treats it quickly is a crucial part of your protection plan. GardenTech® Daconil® Fungicide, with the active ingredient chlorothalonil, provides protection against a broad spectrum of fungal pathogens and simplifies controlling fungal disease from your garden.

Used as a preventive and an active treatment, Daconil® Fungicide can prevent, control or stop more than 65 types of fungal disease on flowers, vegetables, shrubs, fruit and shade trees.

Agaricomycetes

Scales or shell-like bumps on plant stems and the underside of leaves. These are the outer coverings of scale insect. Large populations may result in poor growth. Some species of scale insect excrete honeydew, which accumulates on the upper leaf surfaces. This can be colonised by a black non-parasitic fungus known as sooty mould. Some scale insects deposit their eggs under a covering of white waxy fibres in early summer.

Check susceptible plants frequently from spring onwards so action can be taken before a damaging population has developed. When choosing control options you can minimise harm to non-target animals by starting with the methods in the non-pesticide control section. If this is not sufficient to reduce the damage to acceptable levels then you may choose to use pesticides. Within this group the shorter persistence pesticides (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife than those with longer persistence and/or systemic action. Light infestations are of little consequence and can be tolerated. The best time to treat heavy attacks is when the more vulnerable nymphs are present, for many scales out of doors this is during mid-late summer. Scale insects on indoor plants can breed all year round and so there is no best time of year to treat. Note that dead scales can remain firmly attached to the plants. The success of any treatment can be gauged by the extent to which new growth remains free of scale insects.

To get rid of scale insects prune and dispose of infested branches, twigs and leaves. When scale numbers are low they may be rubbed or picked off of plants by hand. Dabbing individual pests with an alcohol-soaked cotton swab or neem-based leaf shine will also work when infestations are light.

Coccoidea

There are many symptoms of aphid damage, including decreased growth rates, mottled leaves, yellowing, stunted growth, curled leaves, browning, wilting, low yields and, eventually, death. Along with the loss of plant juices from direct feeding, aphids can spread diseases.

1. Monitor your plants. Beginning early in the season, check your plants frequently for the presence of aphids, paying close attention to plants you've found aphids on before. 
2. Check for ants. 
3. Plant onions. 
4. Don't over fertilize your plants.

Ditch-stonecrop

(Penthorum Sedoides)

What is the plant

Planting

Water

Soil

Sunlight

Professional care guides

Possible diseases

More plants

Have a problem with such plant? You can contact one of our botanists