(guest post by Victoria Smith for Sod Solutions)
For many homeowners located in the southern two-thirds of the United States, warm season lawns are trying to make it through the intense summer temperatures during the months of June–August. Although the first day of fall isn’t until September 22nd, mid to late-August is the best time to start preparing for winter. However, you can take steps to prepare for the winter anytime during the fall season.
First, it is important to know the difference between warm and cool season turfgrasses. Warm season grasses typically go dormant during the winter months whereas cool season turfgrasses go dormant in the summer months. When turfgrasses go dormant, they turn a straw-yellow/brown color. For this reason, it is common for many homeowners to overseed their warm season lawns like zoysia, bermudagrass or St. Augustine with a cool season grass like ryegrass before the onset of winter temperatures. Both cool season and warm season grasses enter dormancy, but this blog will mostly focus on ways to keep a warm season lawn green during the winter. Aside from overseeding, there are actually numerous ways to do this. Read on for a few professional tips and tricks you should start practicing now to have the best lawn during the winter.
What is turfgrass dormancy?
As previously mentioned, turfgrasses enter a stage of dormancy in which the grass turns a straw-yellow or brown color. During this time, the grass is in a state of hibernation, in which it requires less water and focuses resources on the roots underground that won’t be as affected by temperatures above ground. For warm season grasses, the turfgrass will go dormant during the winter and keep its roots alive so that it can grow back in the spring, whereas the blades above ground may experience freezing temperatures. Cool season grasses in the northern climates of the United States perform the same way, but during the summer when turfgrass experiences hot temperatures. It is important to note that during dormancy, your turfgrass is not dead. It is simply in a state of “sleeping” and any nutrients applied to it with a fertilizer will not be effective. It is better to feed your grass the nutrients it needs for root health before it goes into dormancy for this reason. We will talk more about this further down in this article.
Pictured above: EMPIRE® Zoysia, a warm season turfgrass, in dormancy.
What are some ways to keep my warm season lawn green during the winter?
There are numerous strategies you can perform to keep your lawn green during the winter. Some of the most popular of them include overseeding a warm season turfgrass variety with a cool season variety or applying a turf colorant.
Where warm season grasses go dormant, cool season grasses flourish and vice versa—making overseeding a great strategy for keeping dormant lawns green. When it comes to overseeding your warm season lawn with a cool season variety, it is important to actually overseed at the right time of year. If you wait too long into the fall season and miss the overseeding window, your grass seed may not germinate in time. Overseeding should be performed when the days are warm enough to grow grass seed and around 30 days before your first frost. This timing will vary depending on where you are located, but generally, the first day of frost in the southern two-thirds of United States occurs around the first few weeks of October. This is why it is important to start preparing for overseeding now. To overseed, you will need to purchase grass seed and apply at the recommended rate on the bag with a broadcast or drop spreader. Covering it with straw, mulch or topsoil may help to protect it from birds. For more information on how to overseed, read How to Properly Plant Grass Seed.
Applying a turf colorant to your dormant lawn will not damage or harm it. Turf colorant can be applied at anytime, but its purpose is to help you maintain winter color during these cold months of the year. This can be done anytime after your warm season turfgrass has entered dormancy. Turf colorants like Endurant should be mixed in a handheld garden sprayer for small and average-sized lawns or a backpack sprayer for larger lawn areas. You will also have a choice between a few different shades to pick from. For more information on using turf colorant as a way to maintain winter color in warm season lawns, click here.
Pictured above: The color difference between a winter lawn with and without turf colorant.
What is the best grass for overseeding?
Generally, perennial and annual ryegrass are the best options for overseeding dormant lawns in the southern two-thirds of the United States. Ryegrass will provide a green cover during the winter when your warm season turfgrass goes dormant. Another benefit to ryegrass is that is adapts well to either sun or shade. There’s a difference between annual and perennial ryegrass though. Annual ryegrass is often cheaper, but perennial ryegrass has more desirable turf characteristics and disease resistance, which is helpful when temperatures change and disease becomes more prevalent in the spring. Annual ryegrass is usually lighter in color when compared to perennial ryegrass, it’s usually coarser in texture and it dies out more quickly than perennial in the spring. However, perennial ryegrass lives longer into the spring and summer compared to annual ryegrass—specifically in shade—which can be a nuisance for some homeowners. You can often find annual and perennial ryegrass seed as a blend as well. See a few of our recommended ryegrass seed options below or browse through our seed varieties we offer online.
What kind of fertilizer helps protect my lawn from harsh winter temperatures?
As previously mentioned, you will not need to fertilize your warm season, dormant lawn during the winter. Your grass is in dormancy and unable to absorb any nutrients at this time. The fertilizer will just sit in the soil without bringing about any benefits to your lawn and serve as a waste of money. The fertilizer may even run off into your ponds and drains when it rains or when snow melts. It is better to feed your grass the nutrients it needs for root health before it goes into dormancy for this reason as the roots and rhizomes will continue surviving throughout the winter. More specifically, the roots and rhizomes are what will cause your grass to grow as it comes out of dormancy in the spring. Protecting and providing them with the nutrients they need before dormancy is of upmost importance.
Sod University recommends two different fertilizer options for the fall. You will only need to use one of the two options for fall fertilization. With bottles of Boost, Maintain and Recover, the Fall Fertilizer Box by Lawnifi® is a liquid fertilizer program powered by Catalyst Technology to help plants better absorb nutrients with the use of less product. Boost serves to revitalize the green leaf blade color after the heat stress of summer, while Maintain and Recover give your lawn well-balanced nutrition by fortifying root zones and preparing your lawn for winter dormancy.
Lawnifi Foundation is a slow-release granular fertilizer option that comes in a 25 pound bag and lasts for three months. With a 29-0-5 NPK formulation, Lawnifi Foundation is the perfect granular fertilizer for lawns and gardens. The two percent iron included in Lawnifi Foundation’s mixture helps plants carry oxygen throughout the leaves, roots and other parts of the plants to promote a green, healthy lawn. Featuring slow-release nitrogen, Foundation gradually feeds your lawn over an extended period of time without overwhelming your lawn with nitrogen during the fall. Both Lawnifi Foundation and the Fall Fertilizer Box cover 5,000 sq. ft.
It should be noted that once your grass enters dormancy, it isn’t dead and could still use a very light watering. In fact, a protective coating of water allows for temperatures to freeze the water in place of the grass roots. About a fourth an inch of water per week is usually enough.
If you have a warm season turfgrass, it is important to start practicing these tips and tricks now so that you can be prepared for winter dormancy. Waiting too late into the fall to overseed can prove to be unsuccessful for seed growth. A firm understanding of winter dormancy can also help you protect your lawn from freezing temperatures and encourage fast spring green-up. Not to mention, having a green yard when your neighbor’s grass is dormant helps your lawn stand out and look its best—even during the winter months.
Want to learn more about achieving a great lawn? Check out more Sod University tips here.
Editor's Note: Sod Solutions has helped successfully develop and release to the market over 20 different turfgrass varieties over the past 27 years including PalmettoⓇ and CitraBlueⓇ St. Augustine, EMPIREⓇ and InnovationTM Zoysia and CelebrationⓇ, Latitude 36Ⓡ and NorthBridgeⓇ Bermudagrass. The company is based in the Charleston, SC area.