We’ve all been looking forward to the warmer weather and the chance to lounge in the garden with a nice book, soaking up those good vibes and vitamin D. But as summer kicks into full gear, all that heat might be a little too much for your perennials. These are the plants you expect to give you years of enjoyment, so it’s important to keep them protected from the short- and long-term effects of heat and drought stress. Here’s how to keep your perennials as happy as you are with the upcoming sunny days.
Signs of Perennial Stress
You can obviously tell your garden is headed into drought season from the rising temperatures, but here’s what you need to look out for while your perennial flowers are weathering the heat. Signs of drought damage are yellowing and browning, leaf scorch and early fall color. Keep an eye out for pests and disease; these will appear more readily on drought-weakened plants. However, if your plants are experiencing dieback and damage, don’t panic. There’s a lot you can do to help them through the season.
How Much to Water Your Perennials
Like every other time of the year, your plants need just the right amount of water during a heatwave. Typically, the ground dries a lot faster right now, and to keep it strong and healthy enough to take on the heat, it’ll likely need twice the amount of water you’d give it during cooler weather. We’d give you an exact measure for the right amount of water, but it truly depends on your plant, your soil, your climate and the weather at the time.
Keep the soil damp, not wet. If your plant is wilting, it may just mean the roots can’t soak up water as quickly as it evaporates from the leaves. A little wilt won’t hurt your plant, and if it’s just drooping in the heat, it should firm up at night—just keep the water coming regularly. Morning waters are typically the way to go here, and you’ll want to water slowly and deeply to get those roots digging down into the soil, away from the hot, dry surface. Slow watering helps soak deeper instead of the water spreading out over the surface.
It may seem like more is better when you’re watering in the heat, especially if your plants have suffered drought damage, but be careful of overcorrecting. Too much water will starve the roots of much-needed oxygen and promote disease, so don’t leave your perennial flower beds sitting in water. The solution is easy—simply let the soil be your guide. You’ll want to water when the soil feels dry and be conscious of whether you have slow-draining soil.
Protect Your Soil, Defend Its Moisture
Speaking of soil, it’s one of your plants’ greatest defenses in the heat. So, if you want to help your garden through this season, why not bolster the defenses? Compost and mulch are two great ways to make your soil more moisture retentive and protect from the hot sun. With compost, you’re tilling in lots of good organic matter that’s going to help the soil retain the water you put into it much more effectively. Mulch creates a defensive layer overtop the soil, which will protect the surface from drying out right away in the sun, so your perennials will have more consistent access to moisture. If you’re putting down mulch to keep consistent moisture in your soil, you’ll also benefit from its weed suppression, which brings us to our next point.
Weeding Saves Plant Lives
The nutrients and moisture in your soil are precious to the plants that bloom and grow in it – especially perennials. Weeds will compete for this precious resource, and the more of them you have in the garden, the more they’ll take away from your plants. So, while weeding is that never-ending chore, it’s an especially important one right now.
When to Shade Your Perennial Plants
If you’ve got unprecedented heat, or just heat for a short period, you could always put up some temporary shade. Either a sheer curtain, a gardening shade cloth or shade fabric, or even just a bedsheet can cut the impact of sunlight on your plants. Set it up so it’s not directly against your plants, trapping heat and moisture where there should be nice airflow. If you can set it up at least an inch or two above your plants, temporary shade can be quite useful.
Back Away from the Fertilizer
Don’t fertilize during drought. Fertilizer can easily damage your perennials’ roots if they don’t have enough moisture to process it. If your fertilizer contains salt, it’ll actually worsen the plants’ likelihood of surviving drought. Additionally, it’s best not to encourage plants that are already struggling to get enough water to form more leaves and flowers and mass, which will require more water. So, you can put the fertilizer away, and just stick to water. Less work and better for your plants—isn’t that nice?
What to do next
Replanting: You’ve done everything you could, but still lost some perennials this year to heat. Hey, it happens. If you start clearing out and cutting back from heat damage, and you end up with an unpleasant gap, there’s an easy, temporary fix. If there’s still hot weather ahead, there are some good heat-loving annuals, like begonias, to fill in with. If you’re cleaning up after the summer heat and cool weather is on its way, fall favorites like sweet alyssum can keep your garden upbeat and fabulous.
Planting: You’re probably not in the planting stages right now, but fall is next and many of our favorites, like perennial bulbs, require fall planting. So, if heat is a problem in your garden, you’ll save yourself a lot of time and heartache by planning early and factoring temperature into your planting. Those hydrangeas you’ve been ogling will thank you for a planting location with some afternoon shade. Wildflowers and drought-tolerant ornamental grasses are much happier in the hot seat, and you can get some great color from the varieties on the Spring Hill website. Do some research while you’ve got the summer to think on it, and take a look at some of our favorite heat- and drought-tolerant varieties.