How Experts Help Plants Survive the Summer Heat
July 22, 2025

How Experts Help Plants Survive the Summer Heat

You’ve carefully curated your garden for months now. You started your seeds early in the spring, using high quality garden seeds. Everything seemed to be going perfectly. But you got comfortable and forgot to check the weather. Your garden is now a week into a heat wave with daytime highs soaring over 100°F. Your plants have started to wilt; the flowers are maturing much more slowly, and some of the leaves are even turning brown. What on earth has happened, and what can you do about it? 


By July and August in most climates of the United States, heat stress is on our minds. If you’re in Florida, Texas, New Mexico, or other southern states, you are very familiar with the concept of heat stress. However, even gardens in Michigan, Idaho, and North Dakota can experience heat stress if a heat wave comes through and you aren’t prepared for it. This guide is perfect for beginner and intermediate gardeners who want to learn how to identify heat stress in their plants, prevent damage, and grow a more heat-resilient garden.


How to Spot Heat-Stress

Symptoms of heat stress can be subtle if you’re not sure what to look for. From afar, it can just seem like your plants have stopped growing or that you might have a soil nutrient deficiency. But look a little closer and you might see things such as:

  • Wilting in the afternoon (even if the soil is moist)

  • Leaf scorch or browning edges

  • Blossom drop on vegetables like tomatoes or peppers

  • Curling or cupping leaves

  • Unexplained white or bleached spots on fruit

  • Slowed growth or bolting (especially in leafy greens like lettuce and spinach)

Heat-stressed plants are often confused with thirsty plants, but the key difference lies in when they wilt. If they perk up by evening, it’s likely heat, not a lack of water, that’s the problem.

 

Tactic #1: Water Wisely

Water is your plant’s best friend, especially in the heat of the summer. And, when used correctly, it can help to cool the soil down enough to help your plants get through the heat of the day. The key is to water early in the morning (like before 9 am) and to water deeply yet infrequently. You don’t want to be watering the plants multiple times every day, as this can cause root rot. Instead, water deeply enough so that the water penetrates down to the lower roots of the plants. That way, you know that even if the top layers of soil heat up and dry out in the middle of the day, the plants have something to reach for down below to keep them cooler. Avoid watering during the hottest part of the day, as much of it will just evaporate. Similarly, evening watering can invite fungal diseases.


Bonus Tip: Use drip irrigation or soaker hose attachments! These tools deliver water more directly to the roots and avoid getting water on other parts of the plant, which can cause disease spread. You can even get timers to make sure your plants always get the right amount of water at the right time.


Tactic #2: Mulch

Adding a 3-4 inch layer of mulch on top of the soil does wonders for plants. Not only will it keep the soil cooler, but it will prevent unnecessary evaporation, reduce weeds, and eventually add organic matter back into the soil. Use materials such as wood chips, straw, or shredded leaves. It’s one of the easiest ways to protect your plants from heat.

Bonus Tip: Avoid black or dark-colored mulch during the heat of summer. These darker colors absorb heat and make the soil even hotter.

 

Tactic #3: Create Shade

Shade cloth is a breathable fabric that blocks 30-50% of sunlight and is perfect for covering vegetable beds or delicate ornamentals. You can hang it from stakes, PVC arches, or even an umbrella. You can also get creative with household items like old sheets, lattice panels, or garden umbrellas to create shade. For container plants, move them to a shadier spot during the peak heat. The goal is to keep plants in full sun for the majority of the time, but to create shade during the hottest and most intense parts of the day (typically around noon-4 pm).


Tactic #4: Long-Term Soil Care

Healthy soils hold water better, keep plants healthier overall, and can better withstand intense heat waves. Improving the soil will promote stronger root systems, which help your plants handle extremes from the inside out. Add compost to the soil regularly, especially each spring before planting, but you can also side dress (add it on top of the soil throughout the summer). Avoid distributing the soil significantly (by tilling or digging) during the heat of the summer. Save those activities for spring and fall. Lastly, keep the soil covered. Whether with mulch (as described above), cover crops, or ground-hugging plants, bare soil is a heat magnet and dries out quickly.


Tactic #5: Choose Heat-Resistant Species and Varieties

This tactic is more for those who are planning their garden and are not currently in the throes of summer heat. Yet, it’s good to keep in mind! If you know that you are in a high-heat climate that frequently experiences temperatures upwards of 90°F and higher, I highly recommend planning your garden around this from the beginning. Plant heat-sensitive crops early in the spring or in the fall. Save the summer growing for varieties that are known to do well in high heat, such as melons, okra, eggplant, sweet potatoes, malabar spinach, salvia, lantana, and succulents. There are, of course, many more than this, but these are just some ideas. If you’re not sure, you can check with your local extension office for varieties that are known to do well in your area, despite whatever weather you may experience regularly. 


Bonus Tip: In areas with extreme heat, it may be wise to plant in waves. In some places, it’s common to take a mid-summer break and start a second planting in late summer for a fall harvest.



Work With Nature

Having a garden is all about working with nature to bring things to life. The unfortunate truth is that sometimes it takes a failed crop or two (or five) to get the hang of how to grow in your specific area. Experience is the best teacher, and the best thing to do is not to give up! Every garden is a little different, and over time, you’ll learn what thrives in your space and what doesn’t. If it’s July in Florida and you’re trying to grow broccoli, that’s just not going to work. Similarly, growing sweet potatoes in Michigan in May is also unlikely to be successful. You can’t do everything, but you can do the best you can with the resources you have available to you. Grow on, my friends!

 

About This Expert:

Lara Wadsworth is a freelance horticulture writer with a Bachelor's degree in Horticulture and over three years of experience creating engaging content about gardening and plant care. As a wife, mom, and dog lover, Lara understands the importance of balancing a busy life with a thriving garden. She values practical advice and effective strategies that empower beginners and experienced gardeners alike to grow with confidence. Through her writing, she aims to inspire others to enjoy the rewards of gardening, no matter their skill level.

 

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