Planting Resources

How to deal with summer HEAT when there’s no rain in the forecast

In the Midwest, we count the days to summer sun, sometimes from the dead of winter. And when it comes, the sunshine feels like the ultimate treat. That is until the temperatures rise higher and the rain becomes scarcer and everyone is looking for a reprieve. Here’s 8 simple things you can do to deal with summer heat.

Summers in Indiana have been tough on our landscapes. And while dry spells are par for the course, near-drought and drought conditions can affect multiple growing seasons by stunting bud growth and stressing plants’ root systems. It is especially brutal on our newly planted trees and shrubs that require more water and a little more TLC, at least in the short term.

So when you find yourself seeking a cold drink and a little shade to feel your best, here are some things you can do for your containers, landscape plants and lawn to give them some of the same:

1. Plant for heat

When it comes to annuals for your containers, windowboxes or landscape beds, make choices in spring or summer that will require less water. You can still grow and have color in the heat of summer, you just won’t have to use so much water to make it happen. Here are some of our favorites:

You can also use a quality potting soil that’s naturally water retentive and top with a layer of mulch to seal in the moisture.

2. Keep an eye on containers

The beauty of containers is that they can be moved. Move yours into the shade if possible, especially to avoid the hottest afternoon sun. Top the soil in your hanging baskets and containers with a layer of mulch or decorative moss to seal in existing moisture.

The downside to containers is that they dry out faster than the ground. We recommend checking them daily for moisture by poking your finger into the soil to your second knuckle. If you feel moisture or your finger has soil stuck to it, the moisture level is fine. If your finger is relatively clean and you feel little to no moisture, it’s time for a good soak.

3. Soak slowly

The key to watering is to do it slowly and deeply and here’s why: watering too quickly can actually waste water, especially when your soil is dry. The dry top layer of soil can deflect water and send it running off your beds or over the sides of a container, instead of soaking in. Slow, steady watering (even 2-3 passes for container plants) can penetrate the dry outer layer and send water down to the root ball.

A fast deluge of water can also compact your soil, making it even more difficult for your plants to absorb moisture and develop a healthy root system.

By the same token, short bursts of water will encourage the development of shallow roots that are not as strong and are more susceptible to drying out. Slow, deep watering will train your plants to send out roots that will seek moisture and cooler temps deep within the soil.

You can also add in a water-soluble fertilizer like Elements or Root Stimulator every couple weeks when you water for even better results. Elements is all natural and gentle on plants and their stressed roots and Root Stimulator helps keep your plants as resilient as possible.

4. Water early in the morning

In most cases, watering during early morning hours is your best plan. With cooler temperatures and less direct sun, the water won’t evaporate as quickly and you’ll give your plants a good supply to begin their day. If you can’t water in early morning, late afternoon is a good alternative. Just be sure to give your plants time to dry before nightfall to avoid disease and fungus.

5. For landscape plants, remember 1 thing

If you have trouble remembering how much water your new plants need, remember 1 thing. Our rule of 1 means that young and newly established landscape plants need 1 – 1 ½ inches of water per week to maintain development. You can use a rain gauge (even a tin can) to see what, if anything, is coming naturally and supplement to keep your new plants healthy.

An inch of water penetrates about 6 inches in our heavy clay soil. Let your sprinkler or hose run for a while, then dig down six inches to see if you need to go longer or not.

In severe droughts, even established trees and shrubs can show signs of stress. You’ll probably notice some brown leaf scorch along the edges of the leaves, which is very common during dry summers. But if there is an extended lack of moisture (beyond 10-14 days), this can dramatically affect next year’s growth and even spell disaster for your plants, especially if they were already under stress from previous drought, disease or garden pests. To keep them healthy and help them withstand the temps, include them in your watering plan. We’d even recommend doing one deep watering to fulfill your plants’ weekly requirements.

6. Water landscape plants at the dripline

Even though we all know that leaves don’t drink up the water, many of us water a plant as if we’re watering the foliage. In hot, windy weather, this can actually make things worse with plants losing moisture through their leaves. It can also lead to disease.

A better plan is to water your landscape trees and shrubs at or a bit outside of the dripline (i.e. along the outer circumference of the plant branches) where the feeder roots will efficiently absorb the moisture.

7. Mulch to seal in moisture

This one bears repeating because it can really make such a difference. An extra 1-2 inches of high quality mulch (because organic material and ground up pallets are not created equal) can work wonders when it comes to sealing in moisture and cutting down on watering. This is especially important if there are summer water restrictions, but is really a great way to conserve water and regulate soil temperature all year round.

Mulch will also cut down on weeds. Aside from the bother of pulling them, weeds compete for the same water as your plants. The fewer the better.

8. Be smart about your lawn

Your lawn needs an average of ½ to 1 inch of water per week. You can buy a rain gauge or make one of your own, but watch your lawn for some telltale signs its low on moisture. If it takes on a dull grayish cast or doesn’t pop back up after you walk through, it’s definitely in need of a good soak.

It’s important you give your grass a good thorough watering, rather than short, frequent bursts. By watering well, you encourage your grass plants to grow deep roots that can access water and stand up to the heat.

In times of extreme heat and little to no rain, stay off your grass if possible. By limiting traffic (including mowing) you will minimize crushing the leaves and crowns of the stressed blades. If there are no restrictions on watering and you want to keep your lawn green, follow the standard watering guidelines.

It’s also possible to keep your lawn alive without watering as much, something that can come in handy if you’re going on vacation (and don’t have an automatic sprinkler system), there are water restrictions or you simply want to conserve on water. Give your lawn ½ inch of water every 2-4 weeks and you’ll keep the turf plant crowns hydrated. This moisture level won’t green up your lawn in the moment, but it will increase survival during long dry spells. Your lawn should green back up within 1-2 weeks of significant rainfall.