Keeping lawns and landscape plants looking good can be a challenge during the heat of summer. But knowing a few basics, like when and how to water or choosing drought-tolerant plants for around the house, can make it a breeze. (Sam Craft/Texas A&M AgriLife)
Originally published at AgriLife Today, by Adam Russell
When high temperatures and drought hit full force, even experienced gardeners wonder if their landscapes can survive.
Mike Arnold, Ph.D., professor in the Texas A&M Department of Horticultural Sciences and director of The Gardens at Texas A&M, said success through summer isn’t about doing more — it’s about watering smarter, reducing plant stress and avoiding common mistakes.
Many homeowners unintentionally make problems worse by watering too frequently, overfertilizing or responding too quickly to wilting. Understanding how plants respond to heat can help landscapes survive even in extended periods of high temperatures, Arnold said.
Below are his answers to the most common questions homeowners ask during extreme summer conditions.
How does heat and drought affect plant health overall?
Even well-watered landscapes can experience stress, especially under high temperatures, direct sun and if irrigation water has high salt levels.
Stress from heat and drought can:
- Increase susceptibility to pests and disease.
- Lead to long-term damage if not managed.
Monitoring plants and turfgrass regularly is key.
“Being in your garden regularly, even just observant walks around your landscape to look for signs of trouble with your lawn or prized plants, will help you see a problem and intercede more quickly,” Arnold said.
Why are my plants wilting in the heat?
Not all wilting is a sign of serious trouble. Plants can temporarily wilt during the hottest part of the day as they lose water faster than they can take it up. What matters is whether they recover later in the day.
However, prolonged stress combined with drought can weaken plants and make them more vulnerable to pests and disease.
How often should I water my lawn and plants in summer?
One of the biggest mistakes homeowners make is watering too often. Texas A&M AgriLife Extension Service’s app WaterMyYard, which is available online, utilizes data from a network of specialized weather stations to notify users with localized recommendations on watering lawns.
Water deeply, but less frequently. Allow the soil to dry slightly between watering events so roots grow deeper and plants become more drought tolerant.
For a quick check:
- Use the “finger test” in landscape beds and containers. Press your finger into the soil: if it is dry, water; if it’s moist, wait.
- If footprints remain in lawns after walking across the grass, it may need water.
The only exception is newly planted trees and landscape plants, as they may require more consistent watering if they are not established before high temperatures arrive.
“It’s best to give most plants just enough water,” Arnold said. “Plants are resilient, so if they look a little wilted, give them a good, deep soaking and they will bounce back.”
What is the best time of day to water during summer heat?
Key takeaways
- Water deeply, not frequently
- Use efficient irrigation methods
- Avoid overwatering and overfertilizing
- Match plants to heat conditions
Timing matters, especially with sprinkler irrigation. Water in the early morning when it’s cooler. It reduces water lost to evaporation, and it helps avoid any potential fungus issues related to moisture on leaves for extended periods from late evening waterings.
People with salty or recycled water avoid wetting plant foliage because it can damage leaves.
“It’s just best to either set your timer or make it the routine, especially for your lawn, to water early in the morning,” Arnold said. “It lets the water soak in before the heat and sun start baking the ground.”
What type of irrigation works best during drought?
Efficient irrigation systems provide the best results, especially drip irrigation and low-flow systems like bubblers and spray stakes. These systems deliver precise amounts of water directly where it is needed for each plant and avoid salt buildup on leaves from high-salinity water.
Overhead sprinklers can be used for lawns, but efficiency can be improved by:
- Adjusting spray heads.
- Checking water pressure.
- Running irrigation audits.
“Maintaining sprinkler systems and checking how much water they are delivering to an area will make watering more efficient and effective,” Arnold said.
Can you overwater plants in extreme heat?
Yes. It’s a common issue.
Even during drought, too much water can:
- Cause root rot.
- Reduce oxygen in the soil.
- Stress sensitive plants, especially certain trees.
“It’s common for post oaks and other flood-intolerant species to die out because a homeowner is focused on keeping the lawn watered and isn’t aware of what it is doing to their favorite tree until it is too late,” he said.
Need local, expert advice?
Speak with an AgriLife Extension agent about relevant resources and programs tailored for your county.
Arnold cautions against “killing plants with kindness,” particularly when lawns overlap with high value trees, like post oaks, or landscape plants that can be harmed by consistent water or saturated soils.
How does mulch help plants survive summer?
Mulch can be a valuable addition to landscapes. It can add organic matter and keep weeds at bay, but mulch also acts as a protective barrier for soil moisture. About 2-3 inches of organic mulch will help moderate the soil temperature and reduce moisture loss.
“Mulch ideally will help maintain moisture and reduce weeds and competition for resources our plants need,” Arnold said.
However, excessive mulch can block water infiltration and air exchange. Avoid “mulch volcanoes” around trees. This can create conditions favoring disease development on trunks and may serve as cover for insects or rodents that can damage tree bark.
Should I fertilize during heat or drought?
Be careful with fertilizers in summer. Inorganic fertilizers are essentially mineral salts and can add stress to plants already stressed by hot, dry conditions, especially when salty irrigation water is utilized. It’s best to apply fertilizers after conducting a soil test.
What plants do better in summer heat?
Plant selection for your location plays a major role in landscape success. For instance, better-performing plants for parts of Texas could include heat-tolerant annuals and tropical plants, xeriscape plants and varieties adapted to regionally specific rainfall, soil composition and water salinity. Texas Superstar plants include a range of time-tested landscape varieties that historically perform well around the state.
“Picking the right plant for your location and your landscape goals can make a huge difference not only in how they perform, but also the amount of time, effort and resources you have to invest to keep them healthy,” Arnold said. “The goal of a water conscious Texas summer landscape is getting the most pop for the drop.”
Location also matters:
Most plants could benefit from afternoon shade and a break from intense sun. Planting them on the east or southeast side of a shade tree or tall structure should do the trick. You can use temporary shade cloth for sensitive plants but make sure not to let the cloth touch the foliage.
Bonus tip: Don’t forget the gardener
Before focusing on plants, a priority for gardening in the summer heat – take care of yourself first. Don’t push yourself to heat exhaustion or heatstroke.
Stick to these basic tips to avoid overdoing it in the heat.
- Work early in the day.
- Stay hydrated.
- Wear light, breathable clothing.
- Take breaks in the shade to cool down.
“Healthy, focused gardeners make better decisions for stressed lawns and landscapes,” Arnold said.
