Stressed by your plant leaves turning yellow? You’re part of the collective facing the same issues! Our botanists have already lost count of similar consultations on how to fix yellow leaves on plants. Many are quite frustrated because, despite the desperate efforts, these symptoms are often irreversible – yellowing of plant leaves is like a fever in humans, but unlike a doctor prescribing paracetamol for a headache, you will need more than just a plant pill! In this article, we will help you answer why do leaves turn yellow and how to prevent this unfortunate condition.
Reasons Why Plant Leaves Turning Yellow on Indoor & Outdoor
What does it mean when plant leaves turn yellow? To provide a definitive answer is a bit of a challenge, but we will help you sort it out with the following explanations!
Water and Nutrient Absorption Issues
- Overwatering or poor drainage – This simple but widespread mistake is often the answer to what causes plant leaves to turn yellow. Planted indoors, interior greenies often require less watering with less transpiration. Similarly, those fortunate enough to be planted outdoors may also be susceptible to anaerobic soil conditions, often correlated to the lack of drainage or the soil type, such as clay. For this reason, it is best to keep the watering at moderate levels and provide sufficient garden canals or perforated pots for indoor plants.
- Underwatering – You may wonder what do yellow leaves on a plant mean despite all your efforts of watering. The chances are that you might be doing the opposite! Some gardeners are afraid of drowning their plants and watering them bit by bit, resulting in partial hydration of the roots. When this happens, the moisture may not be able to reach the deep roots, which makes your plant vulnerable to dehydration and yellowing.
- Rootbound – Do yellow leaves mean too much water? This is the common misconception of many young gardeners upon discovery of such symptoms. However, it might be an indirect cause because your plant's root may be swirling around its own pot, slowly compressing and depriving itself of important nutrients and moisture. This can eventually lead to yellow leaves on houseplants.
- Nutrient deficiency – Can yellow leaves turn green again? That would be a yes if your plant is simply craving nutrients like nitrogen or sulfur. Potassium and other micronutrients can also result in the appearance of yellow plant leaves. So always make it a habit to prepare the soil well and apply the necessary fertilizers!
- Fertilizer burn – The issue of excessive plant food application or a mismatch of its administration is one of the causes of yellow tips on leaves. When there is an excess of elements in the soil, the other elements can be absorbed into the roots due to their chemical properties. The same is true when a plant is fed with fertilizer during its vulnerable stage, which can lead to stress and shock.
- High soil pH – Yellow leaves on plants are directly associated with soil pH range. Most plants tend to favor the slightly acidic to near neutral level (5,5-7,0 pH). If it's slightly off, elements will have a hard time "traveling" through the roots due to their innate chemical attributes. This issue is less likely to happen with prepared soils with lots of organic matter and is most common in degraded outdoor soils.
- Improper soil medium – Orchids are for chunky bark or moss medium, succulents are for sandy or coarse, while others are pretty happy with a normal one. The unavailability of the right proportions of the plant medium can lead to abnormal water retention, making houseplant leaves turn yellow or even death. However, you don't have to worry about knowing everything, as most houseplants are happy with a cocktail of equal portions of regular soil, compost, perlite, or sand!
Environmental or Growing Condition Issues
- Lack of humidity – Seeing plants turning yellow can be infuriating despite close monitoring of watering and other factors. Growing in steamy rainforests, most tropical plants – which is a huge chunk of the overall percentage of sold house plants – display yellowing of leaves or leaf tips when misty air is below the threshold limit. While it can be challenging to raise it artificially indoors, spraying, grouping plants, or providing home humidifiers is your shield against this overlooked enemy.
- Improper lighting – Lighting is perhaps the misunderstood requirement of houseplants being sold as shade-tolerant. While this is partially correct, some plants require a brighter solar exposure than what’s expected. For this reason, never place a plant too far from the light source, even if it is branded as a low-light one. Similarly, ensure that sun-loving plants are drenched with an ample dose of sunshine.
- Temperature – Most houseplants are mesotherms or those adapted to ambient temperatures. If they sense a broad disparity of temperature range compared to the ones they are used to, yellowing is a common sight to the leaves. For this reason, it is important to place plants in a cozy spot.
- Overcrowded plants – If a plant is pressed tightly against its neighbor or a group of bushy plants share the same pot, it can result in competition for space, sunlight, water, and nutrients. General symptoms would be stunting or yellowing leaves of the less aggressive individual. To make things worse, this can make foliar pathogens or pests easily jump and infect the entire plant population!
- Environmental stress – Moving and transporting plants cause immense stress due to the change of the condition’s variable to which it should acclimatize well in order to survive. Plus, direct thermal damage – yellow leaf on plant caused by the cold or fireplaces – can result in immediate yellowing and tissue damage. To solve this, simply give your plant a break and provide a cozy environment; never transplant it immediately!
- Transplant shock – Fear not if you have just given your plant a new home! Yellow leaves on indoor plants are just average; if you see 1-2 discolorations for a couple of weeks, your plant should produce new leaves as it adjusts to the new soil and environmental conditions! In the future, minimize snipping the root system unless they look spiraling in the pot.
Biotic Stresses
- Root diseases – Leaves on plant turning yellow, observed en masse, are one of the latent signs of root rot. Sometimes, a darkening of the stem neck can be seen. While rotting fungi can infect with regular watering, it is expected that rotting fungi can take hold of the roots in anaerobic or saturated soils. To avoid it, it's best to prepare the soil well, use pots with holes, and observe a proper watering schedule.
- Foliar diseases – Bacterial leaf spot and bacterial and fungal blight are some of the infectious agents that can spread outdoors or indoors. Yellow leaves on plants due to foliar diseases are often common with high humidity, warm temperatures, and prolonged wetness of the leaf surface, which favors germination and entry of these pathogens. Due to this fact, it is important to regulate the watering and humidity indoors by proper ventilation or pruning of brushing branches or clustered leaves.
- Pests – Outdoor or indoor plants turning yellow can be caused by a more advanced group of critters–sucking pests like aphids, mealybugs, scale insects, and other arthropods like spider mites. Feeding under the leaves, they can stay hidden unless there is a thorough inspection. And with that being said, it is important to conduct a thorough inspection before it can leave irreversible damage.
Why Do Leaves Turn Yellow on the Following Most Popular Plants
We will help you get through your issue with indoor plant yellow leaves and some outdoors pals as well! To give you a good grasp of the cause, here’s the most common issue faced by each one:
Snake Plant
- This spiky succulent does not like prolonged wetness in its rooting medium, which can lead to rotting and yellowing of the above-ground parts. In contrast, if left parched for more than a month, it can show similar symptoms, too, with underwatering. So be sure to follow a good watering routine!
- When exposed to harsh temperatures and scorching sunlight, in an abrupt manner, the leaf tips and heat-exposed parts turn yellow.
Monstera
- Monsteras can be disheartening to look at if their spectacular leaves turn yellow–these are oftentimes related to irrigation issues indoors. Inconsistent watering can stress the plant, prompting it to shut down a part of the normal processes in the leaves that will eventually turn yellow.
- If you ask why do leaves turn yellow in the fall or winter – this is expected due to the changes in temperature, lighting, and humidity. However, be sure not to stress your plant that much so it can slowly acclimate and get through the frigid season.
- Soil can also be a problem, especially if it has been growing for more than 2-3 years.
Tomatoes
- Being the most finicky vegetable to grow, tomatoes are very susceptible to various root and foliar diseases such as bacterial wilt, Fusarium wilt, Septoria leaf spot, late blight, and bacterial speck. These issues often stem from bad watering habits (overwatering or always keeping the plants wet), poor soil drainage, and overcrowded plants.
- Nutrient deficiencies like potassium and calcium are also common problems if no fertilizer or organic matter application is skipped.
- Other factors can also include natural leaf wilting (if mainly seen in the lower leaves) or stress from recent transplanting.
Philodendron
- Like monsteras, philodendrons display some worrisome yellowing on the leaves when faced with adversities indoors, including under or overwatering, temperature fluctuations, low light, or low humidity.
- If this particular houseplant's yellow leaves are seen in all parts, it can be due to rotting, a consequence of excessive moisture in the soil, or the lack of drainage.
Hibiscus
- Hibiscus can be semi-deciduous (shed leaves naturally with temperature and lighting variables) when grown in cooler climates, making it quite hard to detect whether it is normal or not.
- It can also turn yellow with watering issues and root diseases, especially when grown in pots without holes or in a garden with clay soils.
Squash
- Outdoor plant leaves turning yellow, in the case of squash or cucurbits, are likely a fault of biotic factors – foliar pathogens such as downy mildew, characterized by the scattered patches of yellowing on the leaves.
- During the early seedling stage, the first set of leaves can turn yellow due to a mix of various factors, such as stress from transplanting, and can be exacerbated by poor soil, watering, and harsh temperatures.
- If it barely grows after several weeks of cultivation, it likely lacks nitrogen and other essential nutrients. These problems are common in soils with low organic matter.
Money Tree
- Being a tropical plant, it is quite sensitive to broad temperature changes indoors when grown in a 4-season climate.
- Watering, water quality, and lighting issues make the plant unhappy, manifesting a generalized yellowing.
- If the plant has yellow leaves seen at the lowest or old ones, then it is likely normal senescence or natural plant aging!
Aloe Plants
- This succulent plant typically turns yellow entirely when there is an advancing rot in the stem neck.
- The lack of lighting and improper watering can also produce a similar discoloration on the leaves, typically appearing both on the old and young leaves.
Spider Plant
- Spider plants with yellow leaves are often associated with nitrogen deficiency or compact soil that hinders the roots from absorbing nutrients.
- Underwatering, poor humidity, and stress in environmental settings also drive similar yellow symptoms.
FAQ
Can yellow leaves turn green again?
In most cases, the leaf turning yellow is irreversible if the symptoms are already in its advanced stage. However, in the case of nitrogen deficiency, slightly yellow-green leaves may develop a deeper color with fertilization.
Should we remove yellow leaves from plants?
Yes, as yellowing leaves are often progressive and costly to the plant’s metabolic system, snipping them out would give the plant a boost to recover, focusing more on the regeneration of new foliage.
Do yellow leaves mean too much water or underwatering?
In most cases, excessive watering and underwatering are the culprits of yellowing leaves on plants. But, it is important to look at other factors, too, such as lighting, temperature, or soil, which have a direct link to the plant’s growth.
Why do leaves turn yellow in the fall?
Yellow falling leaves in autumn are often natural in many deciduous plants. However, some plants may be so stressed by the abrupt reduction of temperature and lighting that they produce abnormally yellow leaves.
Why are the bottom plant leaves turning yellow?
Bottom plant leaves turning yellow could be of natural cause due to its age or suffering from external causes such as improper irrigation, lighting, temperature, stress, and potential root disease.
