How to Help Your Plants Through a Hot Spell
The plants in our gardens can really suffer during summer heat waves. Here’s how to help them continue thriving despite rising temperatures.
Most summers see a period of extremely high heat that not only can prove stressful to plants, but often result in their wilting, burning and even death. When those hot spells hit, we all head indoors to find some comfort, but what should we do about our plants? After all, unless our plants are in a pot and can be moved inside, they’re stuck having to endure the intensity of the sun and heat.
The good news is that there are ways to lessen the damaging effects of a hot spell. And if we aren’t able to ward off damage completely, there are things we can do to help revive a plant that has been “fried.”
Container plants are most at risk to intense heat, as are plants with shallow roots, like annuals. Succulents are pretty tolerant.
To begin, let’s go right to the most important tip for helping your plants combat extreme heat:
1. More Water
Plants wilt and their leaves are damaged in extreme temperatures because the evaporation rate of water from the plant’s leaves increases. To counteract this, you must give the plants more water. For best results, try to do so a day before the hot spell hits.
The time of day that you give your plants water is also important. For example, when it’s hot, replenishing water in the middle of the day isn’t very effective, as perennials and shrubs are channeling all their energy toward moderating the heat — not consuming water. The best time for watering plants is typically in the morning when temperatures are lower. The water the plants receive then will help see them through the day.
One thing you should avoid is overwatering, as it’s also damaging to plants. Soggy soil means you should skip an extra round of watering since it will be more harmful than beneficial.
2. Makeshift Shade
Much like humans seek out shady spots on hot days, shade can also help plants. In most cases you can’t move your garden plants into the shade, but what you can do is bring shade to the plants.
Shade cloth and landscape burlap, found in nurseries and DIY stores, can be used to screen plants from the sun. Simply cut the fabric to size and lay it on top of the plants during the day. Other temporary solutions include placing a portable shade canopy so that it protects part of the garden from the sun. Even something as basic as a patio chair can shield a low-growing plant.
For container plants, consider putting them on rollers so that they can easily be moved to the shade when necessary.
3. Lots of Mulch
Heat doesn’t just affect the parts of the plant you see, it also has an impact on the roots. By mulching around shrubs, trees and ground covers, you’ll not only help keep the soil cooler but more moist as well.
To apply the mulch, spread it about 3 inches thick around your plants, keeping it about 6 inches away from the trunks of trees.
4. Do Not Prune
While you may want to cut off any unsightly sunburned growth on your plants, don’t do it. Those visibly damaged outer leaves are actually serving as protection for the inner parts of the plant by producing shade. Allow the high temperatures to come down before pruning away any sun-damaged areas. To be extra careful, hold off on pruning the damage until summer is almost over.
5. Avoid Fertilizer
As mentioned before, plants dedicate all their energy to combatting a hot spell. This means they aren’t able to expend any energy in making use of fertilizer, which stays in the soil and can actually “burn” the plant. Hold off on the fertilizer until after the extreme temperatures have returned to normal, then simply go back to your regular fertilizing routine.
6. Reviving Plants
Extreme heat can leave you with a plant that is “fried.” How can you tell if it’s hopeless or can be revived?
• Wilting: A wilted plant means that it cannot replenish the water that it has lost through its leaves fast enough — a common experience in abnormally hot temperatures. Plants can usually recover from this, unless they hit the “permanent wilting point.” If that’s the case, then no amount of water will help. But if the plant perks up after a deep watering, then the plant should recover fine.
• Sunburned foliage: Sunburn is another symptom of heat injury. When a plant is burned, check the stems to see if they are pliable or green. If they are, then the plant is alive and can usually recover. Also, if there is some green on the leaves, then the plant can be revived. As mentioned before, do not remove the sunburned leaves until the extreme heat has abated, as they serve as protection for the other leaves. If most of the plant shows sunburn, keep any leaves with green since those areas still function as they should. They’ll work to help the plant grow new foliage.