Preparing for extreme heat is something all Atlanta gardeners should be ready for, and we've got the first big heatwave of the summer heading our way this week. Here are some tips for caring for your plants when temperatures soar.
WATER WISELY
Providing water is the most obvious care requirement, but it’s very important to make sure the water is being delivered in a way that is best for the plants.
Water only the soil, not the foliage.
Water early in the morning or later in the evening so most of the water will sink into the soil rather than evaporate into the air.
Plants that have shallow roots will need water more frequently as the top few inches of soil will dry out faster than soil deeper below the surface.
Don't over-water. It is a common mistake to provide more water than heat-stressed plants can actually use, and this can foster root-rot diseases. We can't stress this enough. Plants will hit pause on their active growing, flowering, and fruiting during extreme heat. Providing more water than they need will cause more long-term problems than letting them become slightly dry.
Remember that plants wilt to protect themselves from heat stress. Don't assume that because a plant is wilting it needs water. It may simply be that you're seeing its natural defense mechanism during the hottest part of the day.
MULCH!
Applying a generous layer of mulch or pine straw (or even fallen leaves in a pinch) will go a long way to regulating soil temperature and moisture content and reducing evaporation and soil compaction. In cases of extreme heat, you can protect shallow-rooted plants such as groundcovers by covering them with leaves, pine straw, or a light layer of mulch. For perennials, shrubs, and trees, mulch up to the plant's crown but don't pile up the mulch too thickly around their trunk/stems. This also helps reduce how much you will need to water, which, in turn, reduces the chances of plants getting root-rot because they're getting more water than they can use.
PROVIDE SHADE
If you have planted containers that you can lift, move them out of the sun and into a shadier spot for the duration of the heatwave. For in-ground plantings that are brand new and thus more susceptible to heat stress, try setting up temporary shade with strips of burlap, lightweight frost cloth, or even old sheets attached to bamboo stakes. For taller plants, a pop-up beach canopy or festival-style tent can provide shelter during the hottest part of the day.
resist fertilizing or pruning
Don’t fertilize or do heavy pruning during times of extreme heat or drought. Fertilizing and heavy pruning induce plants to push out new growth, and that's not what you want during a heatwave or extended dry spell.
PREPARE YOUR SOIL
Keep your soil healthy so it can keep your plants healthy. Plants that are already under stress are more susceptible to long-term damage from extreme heat. If areas of your landscape have soil that's compacted and shedding water rather than absorbing it, use a garden fork to manually aerate and loosen the soil. Then spread a layer of worm castings over the aerated areas. The worm castings will work their way down into the holes made by the garden fork and will slowly start to loosen the soil from the inside out every time it rains or you provide supplemental watering. This helps keep the soil looser so it doesn't get as compacted in the future. Follow up with a thick layer of mulch or pine straw to keep everything cooler and to slow moisture evaporation.
Following best practices for creating a healthy growing environment for your plants is the best way to equip them to handle stress from heat, drought, and extreme cold in the winter.
What to expect when you visit G*H during a major heatwave
The nursery will look a little different for the next couple weeks. We will move as many plants as possible into shady spots throughout the property. We will have pop-up tents set up to cast shade in strategic spots. And we will have shade cloth over areas that aren't usually covered. We have to take even more precautions than the average gardener because all our plants are in thin, black nursery pots sitting on gravel, which can reach temps 10-15 degrees hotter than the ambient air temperature. By contrast, plants that are planted in the ground have the benefit of the insulating properties of the surrounding soil which isn't nearly as hot and which retains a good bit of moisture, especially if well-mulched as discussed above.
So, don't be alarmed if you come in to shop and see things dramatically rearranged for the next couple weeks. We're simply trying to maximize every inch of shade to keep our plants as cool as possible until the heat breaks.
We will also be monitoring the health and safety of our employees, and if it gets too hot to be at the nursery, we will close early. Stay tuned to our social media accounts and our website to check for any changes in our normal operating schedule. We appreciate your patience and grace regarding any unpredictable business hours we may have on some of these dangerously hot days. Be safe out there, Atlanta gardeners!