Keeping Your Plants Alive in Hot Weather

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How to Water Plants in Extreme Heat

If your vegetable garden is struggling in hot weather, we’ll show you how to help your stressed plants cope with the heat this summer!

Smart Watering 

Check soil daily by pushing a finger into the soil. Water if it’s dry an inch or two below the surface. A deep soaking every few days is better than a daily sprinkle on the surface.

Water early in the morning while it’s still cool and evaporation is slow. 

Work soil into ridges around plants to create bowls. Water into these and the ridges will prevent water running away over the surface, giving it time to soak in near the roots. Or sink old pots or bottles into the soil next to plants and water into these.

If you’re unable to water daily in hot weather a drip irrigation system controlled by a timer is a good idea. Keep a close eye on container plants. They may need watering more than once a day, especially in windy conditions. Make sure the water is being absorbed fully into the potting soil, rather than just slipping down cracks between the potting soil and the wall of the container. Pour until water runs out of the bottom of the container, and use pot saucers under containers to retain the water for longer.

Reduce Evaporation  

Mulch after watering with organic material such as compost, leaves or grass clippings to shade the soil and keep the root zone cooler.

Shade the soil with a living mulch by planting densely and/or using plants like squashes that are vigorous or have large leaves.

Stop Fertilizing

Adding nutrients also prompts the plant to grow more, putting them under more stress in hot weather, and they’ll need even more water to process the fertilizer too. Stop fertilizing when it gets above 85-90ºF or when plants roll up their leaves, drop their flowers, or stop producing new flowers.

Provide Shade 

Use shade cloth or other fabric such as old bed sheets pinned onto frames or hoops to provide shade for plants. 

Cool-season vegetables, such as cabbage and lettuce, and fruits, like strawberries, will particularly enjoy the shade from the hot afternoon sun.

Harvest 

Harvesting fruits or leaves promptly will help save your plant’s energy. Harvest partially-ripened fruits such as tomatoes and finish ripening them in the kitchen to give your plants a break. Plants might slow down in hot weather, but yields should increase again once the weather cools.

Learn more about which plants grow best in the heat

About The Author

Benedict Vanheems

Benedict Vanheems is the author of GrowVeg and a lifelong gardener with a BSc and an RHS General Certificate in horticulture. Read More from Benedict Vanheems
 

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Jaci (not verified)

2 years 5 months ago

I am wondering if I could keep my outdoor potted plants by setting the pot into a larger pot that has bark between the two pots. I keep my "on hold" plants in pots buried into my pile of extra bark. They seem to thrive this way. Only watering once a week and the plants never get too hot. Could something like that be done with large decorative pots instead of the pike?

Planting in mulch or putting plants “on hold” in mulch does work for a short time. It works to keep roots cool. However, it’s best for annuals or plants that don’t need to survive a long blooming season. Plants are unable to draw important nutrients from the soil. And the plants will require water frequently, as moisture drains through mulch very quickly. So, if you put the plants in pots of mulch, it’s not a long-term solution. We’re not sure what you mean by putting mulch in between two pots. Mulch should help cool the pots if you place between the two pots. However, I’m not sure it does much more than that.