Grass Dormancy: Is it OK to Let Your Lawn Go Dormant?

Is grass dormancy OK? It seems that almost every summer a time comes when the combination of heat and lack of rain makes it a full-time job to keep the lawn grass looking green and healthy. With the cost of water and effort of mowing, is it worth it? Is it safe to let your lawn go dormant?

Dormancy for a lawn is when you grass turns brown due to lack of water and seems to go to sleep. It is not uncommon for lawns to go dormant in the summer, especially in areas with extreme heat and dry spells. In fact, the grass does this on purpose. When your grass turns brown it is because the grass plants have stopped using energy to grow leaves and, instead, are focusing all of their energy keeping the roots alive. Be careful, though, because an excessive period of dormancy can kill your lawn grass.

Here are some ways to prepare for your lawn for dormancy or treat your lawn when it’s dormant without allowing the grass to completely die.

Mow Higher

When you know the heat or lack of rain is coming or likely, mow the grass at a higher setting – 3” or so. This will help your lawn to live longer with less water and will postpone the lawn dormancy at least a little bit. A longer lawn can stay green through a short heat wave or drought longer than a short lawn, so keeping the grass higher may allow you to avoid dormancy altogether.

Don’t Fertilize

When your lawn goes dormant you should not fertilize it. It is not actively growing and, if you are applying a weed killer, that herbicide can actually harm your lawn in its weakened state. If you do have some weeds that you just can’t stand, feel free to spot treat them or pull them by hand. Of course, even in a drought some weeds will look just fine.

Don’t Let Grass Dormancy Last Too Long

When your lawn goes dormant, it should be fine for at least 4 weeks with little or no rain. This is true for most, but not all, grasses that are used for lawns. If the heat and drought is lasting more than 4 weeks it’s time to water to prevent the grass from actually dying. You should aim to give the lawn at least ½ inch of water each week from this point on to keep it alive. That won’t green it up, but it will help to prevent permanent damage. Don’t forget to count the rain in your water total. If you get a ½ inch of rain in a week you should be good.

What Not to Do

There are some things you should not about a lawn going dormant. First, if you have a new lawn, either from seed or from sod, don’t let it go dormant. In your lawn’s first year especially, it is important to give it the water it needs for the roots to get well established. Second, your lawn is not resilient when it is dormant. You should limit activity on your lawn to a minimum. A lot of traffic could actually cause bare spots or kill parts of your stressed lawn.

Prevent Lawn Dormancy

If you aim to prevent your lawn from going dormant you need to do little more than make sure it gets around 1 inch of water each week. The best way to do this is with a rain gauge to determine the real rain and a measuring cup in your grass when you water to gather the total. In most cases, excluding severe heat, 1 inch of water per week will result in green grass all summer long.

So, is it OK to let your lawn go dormant? Yes, it is. Just be sure not to let it go from dormant to dead and it should green up quickly when the rains come and the temperatures get lower. Grass dormancy is not the worst thing as long as it doesn’t get out of hand.