Proper Lawn care for warm weather.

Question

My lawn is currently struggling in the recent heat wave that has hit the midwest United States. Despite how much I water my lawn resemble more of a desert than a green oasis.

I've asked around and I get conflicting advice. To prevent burning the lawn, some say it best to water in morning while others say in the evening. Some say keep the grass short, others say to let it grow out.

What can I do to prevent my backyard from becoming the first desert in Wisconsin? What is the correct time to water/mow on those really warm days/weeks?

Answer 1

Keep it long to reduce stress on the grass. And water in the early morning to avoid mold or other disease growth that may happen with evening waterings. Beyond that, make sure your soil is healthy. Aerate, dethatch, and reseed in the spring and fall. And train the lawn to go further between waterings with deep soakings rather than frequent short watering. The latter results in roots that grow near the surface and suffer from drought more easily.

Edit: For a deep soaking, I would try to get several inches of the soil (depth) moist for grass (for a tree, you'd want even more). Figure some of it will evaporate, some will quickly be absorbed by the plants, so maybe 1" of water above ground will get you a few inches below ground. You can use the trick of putting a cup in the lawn to see how much water it's received, but I just guestimate it by running the sprinkler for nearly an hour. The key is to not stand out there with the garden hose for 10 minutes only spraying the leaves of the grass and training the roots to stay shallow. With a good soaking, you can go a day or two between waterings, depending on how hot/humid it is.

Answer 2

In the summer, you have two options: Water regularly, or let it go dormant.

Both are valid. Grass is fine going dormant in dry hot weather and it will comeback come cool weather later in the year. Yes, it doesn't look pretty, but it's low maintenance. ;)

If you are going to water, you want to soak it well infrequently rather than light water frequently. The former encourages deeper root growth which will make the grass hardier.

In terms of keeping the grass healthy, cut it on the long side. that helps to shade the turf and keeps moisture in.

As for what time of the day to water, many claim that during the day, it can cause burning. I think that's more of an old wive's tale, though. Ideally, you'd water when it's the least windy, though, so that more of the water hits the grass rather than blows away.

Answer 3

I think in really hot weather it doesn't matter whether you water morning or evening. Grass will soak up the water quickly when the soil is dry. When it does rain it can happen any time and the grass seems to cope. If you have hot days and cool humid nights you could possibly encourage mould and fungal diseases by watering in the evening.

Definitely let the grass grow longer when it's hot. Cutting it only encourages more top growth at the expense of energy stored in the roots. BMitch's answer is excellent.

When you over seed be sure you have the kind of grass that tolerates dry conditions such as a mix of red fescue (Festuca rubra) and hard fescue (Festuca ovina var. duriuscula).

Consider planting native grasses in low use areas such as buffalo grass (Buchloe dactyloides). See here for more detail.

Edit: D.A. has some excellent points. If you choose not to water and let the grass go dormant then this aids in letting weeds get a hold in the turf. Whether this is significant depends on how many weeds are close enough to have wind borne seed blown in.