It’s summer! Here comes not just the sun but the blazing temperatures. Unless you want your plant to be grilled in the scorching sun, knowing what is the best time to water plants in hot weather should be on your list of regular gardening activities. Luckily, with the best advice from our botanists and seasoned horticulturists in PlantIn, completing this task should be fairly straightforward. If you are ready, grab your watering cans and garden hose, and let’s fetch a bucket of information about the tips, methods, and the proper timing of irrigation!
Do Plants Need More Water in Hot Weather?
Like humans, plants are delicate creatures that thirst for more water under the basking heat of the sun. Generally, typical plants lose moisture through the tiny holes in their leaves (stomates) in a process called evapotranspiration. If it's hot, this water-requiring metabolic process shoots up at a staggering rate. Numerous plants are equipped with drought-mitigation mechanisms to slow it down, but for many, it means drooping, wilting, irreversible dryness of the tips, and even death. In simple words, hot weather will make an average plant demand more water.
What Is the Best Time to Water Plants in Hot Weather?
Plants have evolved with varying watering requirements, but fortunately, you only need to know a few tricks to know the proper timing of irrigation.
Situated under the searing heat of the sun, plants outdoors tend to be more thirsty than roofed, shade-loving greenies. Hence, it is crucial to know each watering needs, as indicated in the following:
If there is any hardy plant in your garden, then your turf grass claims the top spot! Planted to withstand immense foot traffic, drought, and diseases, these creeping green mat does not need frequent watering. Turn on your sprinklers and time the watering duration in the morning, estimating that the water has seeped about 1-1.5 inches (2-3 cm) weekly, about 30-35 mins of sprinkling (manual or automated) while it is also highly recommended to go about 6-8 inches (15-20 cm) to hydrate its deep roots in the event of droughts. Overwatering terrified? Don’t be! Simply divide that quantity by about twice weekly.
Each flower species has varying rates of watering. However, most of the blooming perennials require average to little watering! For instance, azaleas, hydrangeas, roses, and crepe myrtles should be watered 2-3 times weekly: thorough enough to reach the soil depth of 18-20 inches (46-50 cm), ideally in the morning. That’s about 1-2 gallons weekly (4-8 liters) and can be sprinkled on two occasions. Their roots are deep enough to independently scavenge underground sources of water. For flowering bulbs, just maintain a damp garden bed not to promote rotting, which is approximately half of the moderate drinkers’ needs.
Herbs are chiefly a large group of aromatic, herbaceous, or non-herbaceous plants characterized by two distinct water requirements. If you are watering the traditional kitchen essentials like basils, mint, and oregano, or the ones with “smooth” leaves, give them 2-3 occasions of weekly soak – literally submerging a perforated pot in a bucket of water and draining them after, if the soil appears dry. On the other hand, Mediterranean beauties like lavenders, rosemaries, and sage will only want to be watered 1-2 times weekly, targeting a depth of 10-15 inches (25-38 cm) during their first few days of establishment. Reduce the frequency when their roots already took hold on the ground.
Trees, Shrubs, and Bushes
Large trees, ginormous shrubs, and established bushes don’t bother with the volume and frequency. Thanks to their deep roots, they can already scour water underground. Monthly or bimonthly frequency should suffice if you see some scorched leaves on your trees. Be generous enough with the volume, approximately 3-4 gallons (11-15 liters), to reach the deep subterranean roots. While drought and baking heat can crisp up their leaves (trees and medium-sized shrubs), they will regrow once the favorable conditions return.
Cacti and Succulents
Outdoor arid plants like cacti and succulents are simply built to endure hot weather. They store water that would be enough to keep them alive during drought periods. Succulents like jade plants, aloe vera, snake plants, and echeveria can be watered for about 2-3 weeks or up to a month. If potted, bottom-watering is recommended as the soil can get hydrophobic when left totally dry.
Watering indoor plants may be a bit tricky for some, but it is quite a straightforward manner on hot days. To quench their thirst, do not be afraid to drench an overflowing amount, literally until you see it drenching from the bottom. Depending on the heat intensity and humidity at home, your plants may demand 2-3 times of deep watering. Most tropical houseplants love a thorough soak!
Is it Okay to Water Plants in the Hot Sun?
Watering under the sizzling heat is quite acceptable for big plants. However, for small plants with non-woody stems, like turf grasses and herbaceous flowering and non-flowering plants, this practice could spell disaster. The sudden splash of cool water may dampen the ground but could stress above-ground parts due to the cold-heat fluctuation, resulting in leaf cupping or wilting, premature defoliation, and flower abortion.
Does Watering in the Sun Burn Plants?
Watering under the plain heat of the sun will not immediately cause sunburns. However, this is one of the risks when doing this periodic gardening routine at noontime because plants get tensed. When they do not recover, you may see scorching, primarily on the leaf edges, as a consequence of stress.
What Temperature Is Too Hot to Water Plants?
Plants possess temperature-regulating architecture that keeps them significantly cooler than their surroundings. Most plants can withstand 86-100°F (30-37°C) and, in fact, the Goldilocks zone to perform photosynthesis. However, the intense and prolonged heat waves due to climate change will leave the plants shocked and more prone to temperature fluctuations. Temperatures above the ideal range may denature proteins and enzymes, arresting their metabolic process and could therefore lead to wilting and drying.
Tips for Watering Plants in Hot Weather
While watering your garden is unarguably not the most challenging job in the world, we will give you some tips below on how to make it even easier!
Should we Water the Garden Every Day?
You can water your garden daily but do it in lesser quantities, especially if the soil is well-draining and sandy. As water retention is pretty low, it should be counteracted with daily watering. Conversely, if the soil texture in your garden is loamy or clayey, you might need to check it first with your hand or with a moisture meter to know the true status of the soil. Average soils in hot weather usually will need to be watered every 2-3 days.
How Much to Water Plants?
The volume largely varies depending on the size of the plants. For smaller herbaceous plants that usually have a shallow root system, they need to be watered about 2-8 inches (5-20 cm) deep. Doing the math, it should be multiplied by the area of the root spread. However, if you do not want to compute it, simply estimating it by volume, approximately 2-3 quarts (2-3 liters) should not be an issue.
Should we Water New Plantings More Frequently?
Newly transplanted seedlings are yet to send auto-sustaining roots into the ground; hence, they require more close attention with watering. Sprinkle a generous amount such that the soil stays wet. Never let it dry! Once established, cut back the watering volume and frequency. This is true for many perennials, such as lavenders and other low-maintenance bushes.
Do we Use Automatic Sprinklers vs Manual Gardening Hose?
The difference between automatic sprinklers and manual garden hose is the flow rate accuracy or the amount of water being released. However, unless you live in a region where water is pretty scarce and each drop counts, selecting which or which is completely up to you. Your plants at home only absorb the water it needs, and the rest usually drains down through the bedrock with gravity. Besides, traditional watering hoses are more economical than sprinkler systems.
Is it Best to Water in the Morning or at Night?
Various references contradict whether watering at night or day is beneficial. Daytime irrigation can affect many plant processes, such as evapotranspiration, but will have no observable effects in terms of growth, although some factors can also contribute. On the other hand, nighttime watering is proven to be a water-saving practice, but the drawback: it may increase the risk of diseases such as in turf grass. So what is the best then? Again you will need to weigh the pros and cons. If water is a precious resource in your locality, nighttime irrigation might be a good way of being ecologically friendly. Otherwise, we would not be risking the health of your plants.
Supplies to Use
The good aspect of watering is you can do it with any supply, but if you are looking for a piece of specific equipment that will facilitate the job, the following list should help you get started:
- Watering cans
- Sprinklers (automatic)
- Garden hose
- Multipurpose hose nozzle
- Bucket (for bottom-watering potted plants)
How Often Do you Water Flowers in 90 Degree Weather?
Water your plants more frequently, about 2-3 days apart, if the soil is rich in organic material. If it is a bit sandy, you can water it roughly every day to keep the ground moist.
How Often Should I Water my Garden in 100 Degree Heat?
Watering plants in 100-degree heat must be done daily, especially if the soil has no ground cover. If your plant is relatively new, herby, and non-woody (stem), it needs more water compared to established bushes and tall plants.
Is it Better to Water Plants in the Morning or Evening?
Morning watering is more beneficial to reduce the disease risk, especially your lawn. But watering at night can be an eco-friendly way to make the best use of your water. Most houseplants, on the other hand, can be watered anytime.
What Is the Best Time to Water Plants in the Summer?
While it can be a bit subjective when is the best time to water, to minimize the likelihood of fungal diseases, it is best to water plants in the morning.