What to Do After Extreme Heat Wrecks Your Garden

Water, wait, and see is the best approach.

July 28, 2022
Photo by James Ransom

A few summers ago, not a single one of my pole beans bloomed, which is odd because they are one of the most dependable, fuss-free things to grow. I later realized that it was simply too hot. Temperatures above 90°F slow down plant growth, and temperatures above 104°F put plants under serious heat stress. A plant under stress does not waste energy blooming—it’s in survival mode. Once the heat wave was over, the flowers on my beans appeared.

Heat waves are tough even for heat-tolerant and sun-loving plants such as tomatoes and watermelons, so it’s only natural when a garden takes a beating from record-high temperatures—even if you watered it properly during the heat wave.

And while you might have to swallow some losses, this is not the time to give up on the garden you worked so hard to plant—there are a bunch of things you can do to bring your plants back to life. Here’s how.

Give Container Plants a Good Soaking

Take care of any plants in pots or window boxes first, as they are the most vulnerable.

Slowly immerse smaller pots in a large bucket of cold water. Initially there will be a lot of bubbles coming out of the pot, but as the soil gets saturated with water, they will subside. Once the pot feels heavy, remove it from the bucket and let it drain thoroughly. Water large containers and planters slowly but deeply until water runs out of the drainage holes.

After soaking your container plants, place them in a shady location until they look revived. For containers that are too large to be moved, create a temporary shade protection, for example by positioning an umbrella over them, or putting a deck chair covered with a beach towel in front of them.

Water and Watch Your Veggies

Provided that you have watered your garden during the heat wave, chances are that most plants will have survived, even if they don’t look their best.

First, assess which plants are completely shriveled up, parched, or collapsing, and thus clearly dead, and which ones only show wilting and other signs of heat stress. Water all the plants that are not dead slowly and deeply. Early the next morning is usually a good time to tell which ones you were able to revive, as the lower nighttime temperatures help plants recover.

Go easy on cutting off any leaves that don’t look right. Rolled or cupped leaves on corn and tomatoes are a protective mechanism of the plant in hot weather to reduce the leaf surface and thereby minimize moisture loss. Squash and other plants with large leaves have a different, equally smart trick to deal with heat: The edges of their leaves dry up but the leaf as a whole stays functional. Stripping a plant of those leaves, which usually recover after the heat wave is over, deprives the plant of its ability to perform photosynthesis.

If you haven’t weeded your garden, or mulched around your plants, don’t delay—do it now. By pulling weeds, you remove major competitors for water and nutrients. Mulching conserves soil moisture, keeps the soil cooler, and suppresses weed growth.

Rescue Any Edibles

It does not take a heat wave to make lettuce and other leafy greens, as well as herbs such as cilantro, go into survival mode and develop a tall seedstalk, by which the plant ensures there’s a next generation. This process, called bolting, naturally happens during hot, long days, and it makes the lettuce taste bitter. If that happens, harvest the lettuce right away and taste it; it might still be palatable. If it is only faintly bitter, you don’t have to throw it on the compost pile; the bitterness can be masked by a salad dressing.

The other damage that your garden crops can suffer during a heat wave is sunscald. It usually shows on the side where the vegetable or fruit is exposed to the sun. Sunscald looks different depending on the crop: It can be a discoloration (white or yellow); a soft, watery, sunken, or hardened and dried area; or blisters on the skin. Pick all the affected crops right away, because the damaged surface is an entryway for pests and diseases. If it’s only a small area on a larger fruit, such as on a bell pepper, cut the damage out and use it right away. It is safe to eat.

Back Off on Fertilizing and Applying Chemicals

The general approach is to give plants time to recover after a heat wave. That also means not to fertilize when a plant is in survival mode. Feeding it extra nutrients to trigger new growth stresses the plant out even more. Delay fertilizing for at least a week after the heat wave is over. Also wait for plants to recover from the heat before applying any chemicals to control pests and diseases. Many products (including organic ones) can damage plants when temperatures are consistently above 80°F, so check the label before spraying anything.

Plan for the Next Heat Wave

If you had plants die in the heat wave, try to use this as an opportunity to learn from it and adjust your gardening and landscaping to prevent such losses in the future. If your lettuce got scorched in the hot sun, using tall plants such as tomatoes to cast shade on it during the hot afternoon hours can help protect it from the worst. A special shade cloth also shields plants from the sun.

Or it might be time to rethink your lawn. If your vegetable patch is literally baking in a backyard with nothing but turfgrass surrounding it, consider converting at least part of your lawn and replacing it with native plants that do away with mowing, create a buffer, withstand extreme heat better, and provide a habitat for much-needed pollinating insects. A manicured lawn can act as a mirror, reflecting heat to surrounding plants, whereas native plants absorb and deflect that heat.

Has your garden been affected by a heat wave? Let us know how you're taking care of it.

See what other Food52 readers are saying.

  • Ms Pearl
    Ms Pearl
  • Rhona Gordon
    Rhona Gordon
  • Sadie Kendall
    Sadie Kendall
  • PhenonminalCaliopleigh
  • Smaug
Writer, editor, and translator


Ms P. July 31, 2023
This has been the worst heat wave Indianapolis IN has seen in a long time. I lost some of my greens, by finches eatings them leaving only the stems. My four o'clock flowers have not blossom either.You live and you learn right. I'm going to replant any greens. Any suggestions?
Rhona G. August 9, 2022
I wonder if you could help me here! I have an indoor plant which I believe is stressed due to weather changes. It is a dracaena marginata and there are 7 of them in one pot which I bought several years ago at my local reputable nursery. It's a gorgeous plant! I water it when it gets dry about every 7-9 days. The past few months, even though there is new growth at the tops of all the plants, the bottom leaves are turning yellow and have brown spots on them. Is it due to too much or too little water....too hot? For a few days last month it was extremely hot but it has been rather mild now with no really hot or cold days. I have no idea what to do at this point and don't want to lose the plants!
Thank you!
Gail D. August 9, 2022
That is a normal growth pattern for this plant. As the new leaves form the older bottom leaves die. Just remove the dying bottom leaves.
Sadie K. August 8, 2022
How about shade cloth/row covers?
Nadia H. August 10, 2022
Sadie, Yes a shade cloth is definitely a good idea, I suggested that in my article too. But I would not use row covers to protect plants against heat, as they don't let air through the same way as a shade cloth does and you might end up heating the plants and the soil even more by covering them with a textile.
Sadie K. August 10, 2022
What I do is put the row cover over the plants on top of tomato baskets so there is plenty of air movement. It's just a light weight umbrella. The row cover is lighter weight and cheaper than the shade cloth (which I use, again high up, to cover my herb bed. Tomato baskets have lots of uses.

I made the mistake of trimming some of the leaves of my squash thinking that the squash may. Eed sun exposure, but turns out that I may of inadvertently killed it with the 100 degree days lately. The flowers bloomed but the squash did not grow.
Smaug August 2, 2022
Were you getting female flowers? Those are the ones with tiny squashes at the base; the male flowers are on simple stalks- you need both, and a pollinator, to produce squash. The usual pollinators here are large black bees (I think carpenter bees, but there are a lot of different types); ants love the flowers, but I doubt they have much effect on pollinators.
The notion of removing leaves to expose fruit is pretty common, and almost always erroneous. The leaves produce the plant's food and protect fruit from sun scald (a big problem on tomatoes and peppers in hot areas); if the leaves are no longer helpful, the plant will drop them.
Smaug July 28, 2022
I wouldn't really call tomatoes heat tolerant- they like it fairly warm, but will shut down and drop flowers in the low 90's; they shut down for several weeks in the summer here, but we have a long fall season..
Watering plants may not be the best solution in hot situations, particularly if they're not accustomed to it. They can reach a point where there is plenty of water in the soil but the roots simply can't take it up fast enough. Short of finding some shade for them, it is often best to give them a quick spray of water; this really uses very little water and will cool them down and help leaves rehydrate quickly. I usually do this once or twice on triple digit days, which are frequent here.
SandraH August 8, 2022
Good idea, thanks!