Do you have dead grass or dormant grass? Dormant grass can look scary, but chances are it isn’t as bad as you think. Follow these tips to care for your Dormant Grass.
What Is Dormant Grass?
Dormancy is a naturally occurring period that both cool season and warm season grasses experience, in an effort to conserve water and nutrients. It’s a period of rest during a time of stress which is usually brought on by cold temperatures during the winter, or dry conditions during the summer.
When Does Grass Go Dormant?
It’s important to be aware of when you’re most likely to see grass entering dormancy, remaining dormant, and transitioning out of dormancy. To do this, let’s separate cool season lawns and warm season lawns since the growth calendar is different for these two lawns.
Dormancy In Cool Season Grass
Take a look at the growth chart of a cool season lawn:
Spring
In early spring your cool season lawn makes a huge transition and it does it very quickly. It goes from it’s dormant state that it was in all winter to aggressively pushing out green luscious growth once soil temps hit 50 degrees. Your cool season lawn needs nitrogen more than any other macronutrient at this point. This will get you started with your cool season lawn care program. During the spring, mow often and continue to focus on fertilizers high in nitrogen (and slower release nitrogen if possible).
Summer
The transition from spring to summer is another drastic change in your cool season lawn, especially if you don’t irrigate. Hot, dry weather will cause your grass to slow down. As summer progresses you’ll notice your lawn doesn’t grow as much and you’ll likely be mowing less. You may also notice dry spots and if dry conditions persist your lawn will start to turn brown as it enters summer dormancy. Before your lawn shows signs of stress, start to dial back on nitrogen fertilizers. Instead you want to increase potassium to help prepare your lawn for this part of the year where it will be stressed the most. Stress Blend 7-0-20 is a great way to cut back on nitrogen and increase potassium.
Increase your mowing height and do whatever you can to water your lawn to keep it alive if there are prolonged dry periods. You probably won’t be able to get it green, but at least the roots will be getting enough water to survive. Summer lawn care is a challenge but doing what you can to string your grass along during the summer will pay off big in the fall.
Fall
As the heat of the summer fades, your grass will begin to perk up again. As it starts to green up you can go back to applying nitrogen fertilizers. This will help support blade growth. In late fall, you want to apply a winterizer as your lawn starts to slow down and you mow for the last time of the year. This winterizer should be mostly nitrogen and maybe some potassium.
You may be wondering why nitrogen would be important when we’ve already determined we don’t want to push blade growth while heading into dormancy. That’s because winter dormancy is a little different in cool season lawns. Your cool season lawn is going to shutdown completely over the winter. This includes the root system, crown, and leaf blades. This means the late season application of nitrogen is going to get stored by your grass so it can be used next spring. So think of this winterizer application as an early season nitrogen boost for next spring.
Winter
Once soil temps consistently fall to below 45 degrees, your cool season lawn will enter winter dormancy. At this point the season is officially over and it’s time to wait until next spring. Mow your lawn a little shorter on the last mow of the season and stay off your lawn as much as possible, especially if there is frost. The crown portion of the grass is right at the surface and if that crown gets damaged it won’t grow back next spring.
Dormancy In Warm Season Grass
For warm season lawns, the hot summer months is when grass thrives. For this reason there is really only one dormancy period for warm season lawns. This period is from fall when soil temps dip below 55 degrees, through late winter when soil temps increase above 55 degrees.
Take a look at the growth chart for Warm Season Lawns:
Spring
In the spring, your warm season lawn takes a while to break out of it’s winter dormancy. Unlike cool season grasses, your warm season grass isn’t quite ready for a big dose of nitrogen. When soil temps hit 50 degrees and it’s time to start your warm season lawn care program, start off with applying a pre emergent to block weeds. Once soil temps approach 65 degrees start introducing a little nitrogen but mostly potassium as warm season grass starts waking up. A fertilizer such as Stress Blend 7-0-20 is a great first fertilizer application for warm season grass.
Summer
As you head into summer, this is when your warm season grass will start thriving and this is when you will need to increase the amount of nitrogen. This is when your lawn will be growing its quickest. Mow often, and continue to feed your lawn nitrogen through the summer months.
Fall
As the heat of the summer cools and you head into fall, your warm season grass will respond by slowing down. As it slows down, reduce nitrogen and once again increase potassium. Going back to the Stress Blend 7-0-20 is a great way to wrap up your lawn care season.
Winter
In the winter your warm season lawn is dormant on top but in the soil the roots are still active. There isn’t much you have to do lawn care wise but just know that your lawn will still be looking for water since the roots are still awake. You don’t have to water too often but be aware of prolonged dry periods. Since your lawn is dormant and brown on top you don’t have the visual cue that tells you your lawn needs water. Take a small probe of the soil every one in awhile to see if there is moisture in it. If it is dry and you have the ability to irrigate then do so.
How Can You Tell if Grass Is Dormant or Dead?
Dormant grass can cause a lot of panic since its tan or brown color closely resembles dead grass, or dying grass. But before you panic, make the following observations and perform the following tests:
1. Take a close look– Get up really close to your grass. For cool season grass look at the crown. The crown is the part of the grass that comes out of the soil. You should see some tiny green growth in the crown of the grass once soil temps warm in the spring. Last years grass blades may be brown, but inside the crown should be green as long as soil temps are warm enough. For warm season lawns check the runners along the surface of your lawn. You should see little green growth forming when soil temps warm in the spring.
2. Irrigate- If you have the option to irrigate your lawn then do so. If you’re having drought conditions in the summer, you’ll see the lawn get some of its color back as it gets a much needed dose of water.
3. Observe the consistency- Is the brown grass patchy, or uniform and widespread throughout your lawn?
During the winter dormancy period, dormant grass is usually pretty consistent in color throughout the lawn, or through large sections of your lawn.
For summer dormancy in cool season grass you might see some patchiness since there could be areas of your lawn that tend to dry out quicker due to sunlight exposure and soil makeup. If you have an irrigation system you could have a couple areas of poor coverage and therefor those areas might show signs of dormancy as well.
Overall though, dormancy in cool season grasses tends to be uniform, especially during the winter dormancy period.
But for warm season grasses such as Bermuda and St. Augustine, you can get some real funky patterns for the brief periods heading into winter dormancy and heading back out of dormancy in the spring. Don’t be alarmed if you see some of these crazy patterns. Check out this pic of a lawn with Bermuda Grass heading into dormancy:
Even though these patterns are irregular, they should be seen consistently throughout your lawn.
4. Think of temperature and weather conditions- If you see your lawn turning brown think about what the weather conditions have been recently.
Has it been dry during the summer months? Are you coming out of the cold winter months? Is it late fall and temperatures have been really cold, maybe even some mornings of frost? These are all conditions that can cause your grass to go dormant, and therefor will explain the discoloration.
How to Care for Dormant Grass
1. Use the right fertilizers– Don’t apply high nitrogen fertilizers when your grass is in dormancy or entering dormancy. You don’t want to focus on blade growth during this time. Instead, fertilize with potassium heading into periods of dormancy.
2. Control weeds when it’s safe- Chances are weeds such as clover and crabgrass have become a problem while your lawn was most vulnerable, especially during a summer dormancy period in cool season lawns. Once the grass starts to green back up it’s safe to use post emergent herbicides to control these weeds.
3. Mow only as needed- Stay off your lawn if it doesn’t need to be mowed. For cool season lawns mow higher when heading into the summer.
4. Reduce traffic– Do whatever you can to avoid any foot traffic, including dogs.
5. Irrigate– Do what you can to irrigate your cool season grass during the summer months. While temporary browning of the leaf blades is normal for cool season lawns during the summer months, make sure there is at least some moisture in the soil. Prolonged period of drought will eventually kill your dormant cool season lawn. Water is the only real way to save your lawn.
Check Out These Posts Next
The Importance of Soil Temps in Your Lawn
Winterizer Fertilizer: Everything You Need to Know
Top Dressing Lawn: Benefits and Advice
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Thanks for the info. I’m always shocked at how my cool season lawn looks dead after a long winter. But like you said, it always uniform and eventually spring back. I might give organic fertilizers a shot!
thanks for commenting Dan! I’d love for you to give organic fertilizers a shot. They are so much better for building healthy soil and releasing nitrogen slowly and evenly.
Really informative. I never thought to water warm season grass during the winter. Some winters we have little snow for long periods. Very good point indeed!
Thanks very much Alan, happy to hear you found it informative!
I live around Austin and we have little freezes. I wanted to water the roots, bit I was worried about the freezes. It that a problem?
Hi Mitch! I wouldn’t worry about little freezes damaging the lawn where you are. Since you thaw out during the day the water will get to the roots during the day. Having said that, I would monitor the weather and try and cherry pick the days when it is warmer out. You won’t need much water on your dormant lawn so if you can pick out warmer days then do that.