Dead vs. Dormant
It can be pretty difficult to tell whether your grass is dead or dormant. Lots of factors can cause your lawn to slip into dormancy. When grass goes dormant it is doing so in order to save energy and water. This can help it stay alive during harsh conditions. The roots will receive a lot of the moisture and nutrients so that the grass can stay alive. Since the resources are going to the roots, the blades will eventually turn brown.
There are a couple of things you can do to figure out if your grass is actually dead or if you will be able to revive it into a green lawn again.
This is an effective test to determine if your grass is dead or just dormant. Find a section of the brown grass and pull. If the grass comes out easily with little to no resistance, then the grass is dead. If this is the case, you will have to use seed or sod to replace the dead grass.
If your entire lawn is brown, then it could be dormant. However, if there are only brown spots here and there throughout the lawn, then those places are probably dead. It is a good idea to check for patterns that could signify disease or pests. In addition, you can have your soil tested. If it is disease, fungus, or pests then you want to eliminate the root cause before repairing your lawn.
One more thing to take note of is for lawns that are made up of more than one type of grass. This is a very popular method, especially for cool-season grasses. If you have a mixture of types of grasses that go dormant under different conditions, then your lawn could actually appear patchy even if the grass is in dormancy. This is because one type of grass may be dormant while another is still green and growing.
Another way to tell if your grass is dead or dormant is to irrigate. After a few days of additional water, you should notice a dormant lawn turning yellow-green. However, this may take longer if the weather is hot and dry.
Check for Pests
If there are pests in your lawn around the brown spots, there is an increased likelihood that your lawn is dead and that you need to eliminate the pests before reseeding or sodding. Grubs are usually easy to find below the surface of the soil around the dead patches. A lot of birds on the lawn is also a tell-tale sign that you have grubs or other pests.
If the patches seem to appear where people or animals walk often, then that is probably the cause. This is especially true if the dead spots are in areas where the animals urinate. Urine can kill grass and leave brown spots in your yard.
What Causes Dormant Grass?
Typically, harsh conditions cause grass to go dormant. Some grasses go dormant in the Winter while others go dormant in the Summer. It also depends on the region. Cool-season grasses are more likely to be negatively affected by warm, dry weather. Warm-season grasses usually begin to go dormant when the weather gets below 50 degrees, but it can vary depending on the grass type.
Most established, healthy lawns can survive three or four weeks in dormancy related to drought and stay alive. However, if the climate is expected to remain dry for any longer than that, it is best to water the lawn. You should try to water the lawn early in the day so that the direct sunlight does not evaporate as much of the moisture. Water enough to keep your lawn alive. This does not mean that the lawn will become green until the drought is broken.
Northern cool-season grasses can survive cold weather more than warm-season grasses. However, if the weather gets cold enough consistently, the grass will enter dormancy. If the temperature went through a drastic change recently, then your grass could very well be dormant instead of dead.
Usually heat will only affect cool-season grasses. Some grass types will go dormant every Summer. This is especially true in warmer cool-season grasas climates. However, during extremely hot weather, some warm-season grasses will actually go dormant.
How to Revive a Dormant Lawn
There are some things you can do to help speed the process of revival up for your dormant lawn. The main thing is that the temperature needs to be in the range that is good for the type of grass. There is nothing you can do when it comes to that, but there are some other things you can do to help it along the way.
First, grass needs sufficient water in order to be healthy. Most grass can go dormant without water for 3 or 4 weeks. However, you need to continue to water your lawn so that the soil is moist down to the roots of the grass. Typically, this means that it should be moist for 5 inches below the surface to sufficiently water the roots. This will keep the lawn healthy while it is dormant so that it can quickly turn green and lush once the temperature is right again.
Furthermore, before the dormant season begins, you should always make sure that the grass is sufficiently watered. This will increase the chances of survival and prolong the negative effects of drought or other harsh conditions. It is always best to stay on a consistent watering schedule. This makes it less likely that the grass will be flooded or dry out at any time.
Another thing you can do is fertilize your lawn. You do not want to fertilize excessively while the grass is dormant. Some people mistakenly think that fertilizer will help revive their dormant lawn. This is not the case. However, during the growing period, the blades will grow faster and remain healthier if you do fertilize. This will also keep it healthy so that it comes out of dormancy faster. It is best to fertilize at the beginning of the growing season.
Weed control is another important aspect of a healthy lawn. Some weeds will thrive while the grass is dormant. Some grasses go dormant in dry weather while the weeds run rampant. The weeds will take nutrients away from the grass. They will also drink up the water that the grass needs to survive during dormancy. Apply herbicide or pull the weeds out while they are young. This way, your grass can remain healthy while it is dormant and revive faster when the weather is healthy for it.
Also, it may not seem like it is important to mow while the grass is in dormancy or semi-dormancy. However, if you do notice that it is growing, it is a good idea to maintain it as you normally would. Keeping the grass at a consistent height will help it come out of dormancy quickly because the grass will be healthier. The same goes for too much traffic on the lawn. If too many people are walking all over the yard then the blades of grass will be damaged. This can also increase the chance of severe dehydration.
If you do have patches of grass that die while the rest of the lawn is dormant, you need to replace or reseed them. This will help you maintain a full lawn during the entire year.