We’re going to be writing and posting a lot of blogs about hot weather this summer, and with good reason. Temperatures are soaring across the US and Canada right now and many of us with lawns, gardens, and landscaping are struggling to care for them in the heat. Lawn care in hot weather can be a special challenge; the heat complicates everything from watering and fertilizing the lawn to mowing and trimming the grass. With that in mind, we’d like to offer some tips and tricks for hot weather lawn care in order to help us all keep our grass alive and thriving throughout a record-setting hot summer.
Gardzen Executive Summary:
· High temperatures and hot summer sun affect all aspects of lawn and turf care.
· Timing is everything: by mowing, watering, and fertilizing at the appropriate times of the day or the season we can help keep our grass as healthy as possible.
· We can’t beat Mother Nature: sometimes the heat and sun will defeat our best efforts and brown spots or dry grass will result.
· Recovery from these setbacks is absolutely possible and we may have a green lawn again soon.
· Paying attention to our landscaping plants and grass is a must for successful summer lawn care.
Keeping Grass Healthy in Hot Weather
Let’s start with some basics: how to keep grass healthy in hot weather and what goes into ensuring that our lawns can survive the summer heat and recover when the weather cools down.
The first step, of course, is choosing the right type of grass for the climate. Different species of turf or lawn grass—and there are thousands—have evolved or been cultivated in order to thrive under different conditions. Like other plants, lawn grasses will have a FDA climate zone rating that tells us roughly what sort of weather conditions they prefer. Most commercially available grass will also be rated as to their drought tolerance, which is something to consider for those of us in dry climates or climates that occasionally experience drought conditions. By choosing the right grass for our lawn and our region, we’ll be well on the way toward success in hot weather lawn care.
Like selecting the right varietal of grass, this next step is best done in advance. De-thatching the lawn, meaning breaking up the underlying dense mat of living and dead grass roots and stems, goes a long way towards helping a lawn survive in hot weather. By removing thatching, we can help our lawns better absorb water from either rain or irrigation, promote a healthy soil biome, and reduce soil density and thus reduce runoff while increasing water absorption.
Appropriate watering practices are the most important active, season-long step we can take in maintaining a healthy lawn. Most commercial lawn grasses and lawn mixes need about an inch (2.5cm) of water a week to look their best. In hot weather, that may double. During hot weather and dry periods, watering should be done once or twice a week, deeply and thoroughly, in order to best absorb into the soil and become available to the grass roots therein. Generally speaking it’s best to water grass either early in the morning or last thing in the evening in order to avoid losing water to evaporation during the heat of the day. Some folks prefer morning watering, claiming that watering in the evening can promote root damage from fungal infestations. We’ve not seen a lot of evidence for this, but please do what works for you in your climate.
Mowing the grass high is another important step. Ideally we wouldn’t cut our grass at all during a heat wave or drought—the damage mowing causes stresses the grass above and beyond what the heat and dry are already doing. However, since some of us have to mow, it’s best to let the grass get between 4 and 5 inches/10 and 13cm in height and then cut it back to around 3 inches/7-8cm. This additional height helps protect the soil, prevent evaporation, and avoids unduly stressing the grass plants themselves. It’s also best to just leave the clippings on the lawn in hot weather—they provide additional protection and moisture and eventually fertilize the soil.
In hot weather, it’s best to avoid fertilizing lawns. Fertilizers for grasses and turfs are generally designed to encourage growth, and excess growth leads to additional nutrient and water consumption. This is a bad idea when the grass is struggling to stay alive, so apply fertilizers in the fall or spring per manufacturer’s instructions.
It’s important, as we care for our grass, to be aware of both weather changes and watering restrictions. It doesn’t help much to water our lawns when a good rain shower is coming, and ignoring municipal water restrictions during a time of drought is just selfish and dangerous. Awareness is part of gardening and landscaping, and it definitely plays an important role here.
Dealing with Dry Lawns and Brown Grass
Sometimes our best efforts aren’t enough and the lawn goes dry and the grass turns brown. This is absolutely OK and will happen from time to time in hot climates or during periods of hot weather. The good news is that grasses are tough and they have evolved to survive. There’s a good chance that your lawn isn’t dead, but rather dormant. This means that the grass is in a resting, torpor state until the weather cools down and the water returns. The test to see if grass is dormant or dead is simple: grab a handful and pull on it! If the grass breaks away easily, meaning the roots come out of the soil, it may be dead. If there’s some resistance and the grass holds on, it’s likely just dormant. The “pull test” isn’t scientific nor is it definitive, but it’s a good indicator of what’s going on.
Dormant grass needs some care in order to recover. These care steps are best administered when the weather cools down a bit, but they can be effective in bringing grass back from brown to green (or at least healthy) in a few weeks. The first step is to de-thatch and aerate the soil. We’ve discussed de-thatching above, but aerating the soil means poking holes across the lawn’s surface to loosen the soil, increase air flow, and help water absorb more deeply into the dirt. This can be accomplished in a number of ways: some folks prefer to use a spiked aerator to push holes into the dirt. Some like a core aerator, which removes a plug of grass and soil to open the dirt beneath. Both choices have their advantages and will depend on your local situation, so ask a local garden club or cooperative extension office for regional advice.
Now it’s time to water. The good news is this process is pretty simple: one or two deep soaks a week administered either first thing in the morning or as the sun is setting. Dormant grass is thirsty grass and it make take a few weeks to recover, but deep regular watering combined with the other care we’ve outlined will help a lot
This may be the time for some fertilizer as well, but we like to ensure that the lawn is bouncing back from a brown, dry spell before we start adding fertilizers or compost to the soil. It’s best to top dress, particularly after aerating the lawn. Water and gravity will do the rest and your grass will have the fuel and hydration it needs to recover.
If dry grass doesn’t bounce back, it may be time to reseed the lawn. That’s a whole blog unto itself, so we’ll save it for another day.
We hope this advice helps you and your landscaping get through the summer. Stay safe out there, remember to hydrate and use sunscreen when doing yard or garden work, and keep the faith. Cooler weather is coming!
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