Garden Heatwave: How to Care for Heat-Stressed Plants

Reader Contribution by Benedict Vanheems
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Photo by Pixabay/jf-gabnor

Here are a few tips to help you to help your plants cope with hot garden conditions this summer.

Smart Watering

Water early in the morning when moisture evaporates more slowly. Check soil daily and water if it’s dry two or three inches below the surface. It’s best to soak the soil every few days than dampen only the surface daily.

Mold soil into ridges around plants to create bowls to water into. That way, water will be held in place to soak in rather than running away over the soil surface. Alternatively, water into old pots or bottles sunk into the soil next to plants.

Consider using a drip irrigation system on a timer if you’re unable to water daily in hot weather.

Container plants may need watering more than once a day, especially if it’s windy. Make sure the water is being absorbed into the potting soil, and not simply pouring down cracks between the potting soil and container wall. Keep pouring until you see water running out of the bottom. Use pot saucers to retain the water for longer.

Reduce Evaporation 

Lock in soil moisture by mulching after watering using organic material such as compost, leaves or grass clippings. This will help slow evaporation by shading the soil and keep the root zone cooler.

It will also help to plant densely or use vigorous sprawling plants like squashes to create a living mulch that will shade the soil.


Stop Fertilizing

Temperatures above 85-90ºF can cause plants to roll up their leaves to reduce water loss, drop their flowers or stop producing new ones.

At this point it’s best to stop fertilizing, because plants need even more water to process fertilizer. Adding nutrients also prompts the plant to grow more, which is stressful to the plant in hot weather.

Provide Shade

Shade plants with shade cloth or with fabric such as tulle or old bedsheets. Plants will grow more slowly under it, but they’ll be less stressed. Support the shade cloth by pinning or clamping it onto frames or hoops.

Cool-season vegetables like cabbage and lettuce and fruits such as strawberries  will particularly benefit from shading from hot afternoon sunshine.


Harvest fruits or leaves promptly to help conserve your plant’s energy. Finish ripening fruits such as tomatoes that haven’t fully colored up in the kitchen to give your plants a break. Plants might slow down in hot weather, but they’ll return to productiveness once the weather cools.

Get More Tips with These Great Gardening Resources

Our popular Vegetable Garden Planner can help you map out your garden design, space crops, know when to plant which crops in your exact location, and much more.

Need crop-specific growing information? Browse our Crops at a Glance Guide for advice on planting and caring for dozens of garden crops.

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