How to Keep Grass Green in Winter

green grass with snow on top

Depending on where you live, the onset of cold weather doesn’t mean you’re destined for a dry, crunchy lawn. If you have warm-season grass for your lawn, there are steps to keep your grass green until it warms up again. From overseeding with cool-season species to applying specific nutrients to using a turf colorant, we cover the best ways to keep your grass green in winter.

What grasses can you keep green in winter?

Before we discuss the different ways to keep your grass green in winter, it’s essential to determine if it’s possible to try to keep your grass green. Whether or not you can depends on what grass type you have.

If you live in the South or southern parts of the transition zone, you have a good chance you can keep your warm-season grass green with mild temperatures. Unfortunately, there is little chance of keeping your cool-season grass green in the North, especially if you get snow.

Understanding warm-season versus cool-season grasses

Map of the United States showing cool-season grass, warm-season grass, and transition zones.
Infographic by Juan Rodriguez

To understand why you might be able to keep warm-season grass green in winter but not  cool-season turfgrass, it’s important to understand the difference between the two turfgrass classifications. 

These grasses are more tolerant of heat, so their growth doesn’t slow when the sun is scorching in July and August. However, they are less tolerant of colder temperatures. When the soil temperatures creep close to or below 55 degrees Fahrenheit, these grasses start going dormant. They’ll lose their green color once the soil is consistently below 50 degrees Fahrenheit. 

If you have a warm-season lawn (and live in an area where winter temperatures are mild), you have a better chance of keeping it green in the winter, depending on the conditions. Also, some types, like Bermuda, centipede, and Zoysia, can tolerate cooler temperatures better than others, increasing your chances they’ll stay green.

These grasses are less tolerant of heat and drought but more tolerant of winter conditions. They grow best when soil temperatures are between 50 and 65 degrees Fahrenheit and typically go dormant in the summer once the soil temperature climbs above 75 degrees Fahrenheit. Unlike their warm-season counterparts, they continue growing when it’s cooler until soil temperatures drop below 40 degrees Fahrenheit.

If you live in the northern U.S., there is very little chance you’ll keep your grass green once it starts freezing.

Steps to keeping your warm-season lawn green in winter

Keeping your warm-season grass entirely green throughout the winter can be challenging. However, the following tips and techniques can help maintain a greener appearance until spring.

Overseed with cool-season grasses

One of the best ways to keep your southern lawn green in winter is to overseed it with cool-season grass. Plan to overseed in mid- to late October. At this time (and temperature), your warm-season grass is starting to go dormant, and conditions are perfect for germinating cool-season grasses like perennial ryegrass.

Overseeding helps keep your lawn green since cool-season grasses grow at lower temperatures than warm-season types. The success of this method depends significantly on your winter conditions and the kind of lawn you have. 

Areas that typically stay above 40 degrees Fahrenheit will have better results than areas that experience colder temps or regular cold snaps. This practice is also most successful with Bermudagrass lawns. You can do it with other warm-season turfgrasses, but the results won’t be as good.

Water regularly

Man watering green lawn, sprinkling water on the grass with water pistol
rh2010 | Adobe Stock Free | License

If temperatures hover around 50 degrees Fahrenheit and you want to keep your lawn green, periodically watering it may help. 

Dara Clark, PhD, an Associate Professor of Water and Soil Relationships in Turfgrass Systems from Clemson University, recommends, “For warm-season grasses, apply 1-inch of water if no rainfall has occurred within 3-weeks.” You could also break this into shorter periods and give your grass a half inch of water every ten days during winter.

With this tip, it’s important to note that watering your warm-season grass will not prevent it from going dormant. However, the added moisture will help reduce stress symptoms and keep the root system healthy. Coupled with the other tips mentioned here, it can improve the chances of maintaining a green lawn through winter.

Pro Tip: If you need help determining how long it takes to water your lawn to give it the right amount of moisture, you can do the tuna can test. According to one of our articles on how often to water your lawn, you’ll place empty tuna cans across it, turn on the sprinklers for 15 minutes, and then measure the water in each can. Add the amounts together and divide the total by the number of cans to determine how much water your sprinkler supplies in 15 minutes. 

Apply nitrogen fertilizer before it gets cold

A dose of nitrogen fertilizer before the first cold snap can help warm-season grasses retain some color. The best time to apply is early to mid-fall before soil temperatures drop below 55 degrees Fahrenheit. 

Nitrogen is a critical component of chlorophyll, the pigment responsible for green grass. Applying nitrogen in early fall encourages the grass to produce more chlorophyll, maintaining a deeper green color. It may also cause a surge in growth, extending the growing season longer than usual.

Choose a granular fertilizer versus liquid, as a granular formulation typically (but not always) releases nutrients more slowly. Use it at the recommended rates, and water it into the soil well.

Pro Tip: This fall fertilizer application should contain more nitrogen (N) than phosphorus (P) and potassium (K) or similar ratios of N and K. It isn’t the same as the winter fertilizer you use when winterizing your warm-season grass to keep it healthy during dormancy, without concern of keeping it green. The purpose of this dose is to produce chlorophyll and spur growth, both of which are triggered by nitrogen. A winter fertilizer should have more potassium than nitrogen to promote root growth and improve disease and stress resistance versus triggering above-ground growth. 

Give it a boost of iron

Apply a liquid or granular iron supplement early to mid-fall, just before your warm-season turf goes dormant for winter. The best time to do this is when daytime temperatures are consistently between 70 and 80 degrees Fahrenheit and nighttime temperatures hover around 50 to 60 degrees. Depending on your location, this is typically late September or early October.

Iron is a crucial nutrient for lawns because it is a critical component of chlorophyll, the pigment that makes plants look green. When an iron deficiency is present, you’ll see your lawn take on a yellowish or yellow-green hue instead of the lush green color many homeowners strive for.

Note: The iron won’t keep your grass actively growing, but it will help it maintain its green color for longer.

Choose a product with chelated iron, and always follow label instructions for application rates and safety precautions. 

Liquid iron products typically cost between $20 and $50 for 32 ounces; granular products cost approximately $25 for a 15-pound bag.

Raise the mower deck and mulch clippings

Lawn mower cutting green grass in backyard, mowing lawn
Mariusz Blach | Adobe Stock

As you approach the end of your regularly scheduled mowing for the fall season, one of the best mowing practices you can implement for the final mowing(s) is raising the mower deck and mulching the grass back onto the lawn.

Keeping a slightly longer blade length — one-half to one inch longer than the recommended cutting height is sufficient — and covering the soil with mulched grass clippings adds some nutrients back into the lawn, helps the soil retain more moisture, and reduces stress on the grass. In turn, helping preserve the color longer.

If you mow through the winter, keep that mower blade height slightly higher until temperatures warm in the spring and grass growth takes off. 

Use a turf colorant

Some might interpret the final way to keep your grass green in winter as “cheating,” but if green is your end goal, you can consider applying turf colorant or grass paint. The ideal time to use it is just before the grass enters dormancy.

Turf colorants are specially formulated dyes or pigments that give grass a natural green appearance when it is not growing naturally or is discolored due to damage, pest problems, or disease. It’s critical to remember the crucial part of that sentence: turf colorants don’t make your lawn grow; they are purely aesthetic.

Look for a product that closely matches your grass type. Use a weed sprayer (after making sure it’s thoroughly cleaned) to apply it, carefully following the product directions. Apply it in a circular motion to ensure an even application and prevent streaking.

Depending on the type of colorant you opt to use, expect to pay between $30 and $100 per gallon. For help choosing a grass paint, read our article on the 6 Best Grass Paints of 2024.

FAQs about keeping your grass green in winter

Should I aerate my lawn before winter to help it stay green?

In most cases, you should avoid aerating warm and cool-season grasses in late fall. The best time to aerate is when your lawn is actively growing so the grass quickly recovers from the stress: warm-season grasses in late spring and cool-season turfs in early fall.

However, if you are overseeding your warm-season lawn with perennial ryegrass or another cool-season turf species, you should aerate before overseeding to help improve seed-to-soil contact and germination.

How long does turf colorant last?

Turf colorant, or grass paint, lasts between six weeks and three months, depending on factors such as the product quality, how fast your grass grows, the amount of precipitation, and the amount of foot traffic your yard sees. 

Can you spread compost to keep your warm-season grass green?

Spreading compost across your lawn is fantastic for soil health, but it doesn’t prevent warm-season grasses from going dormant or keep them green through the colder months. A better bet is to mulch grass clippings back onto the lawn along with the other tips mentioned.

Need help getting your grass ready for winter?

With all the tips mentioned above, your lawn care to-do list likely got considerably longer. If you’re determined to keep your grass green and need help overseeding or applying fertilizer, we have you covered! Reach out to LawnLove, and we’ll put you in touch with a local lawn care professional. They’ll help prepare your warm-season grass for winter so it stays green and looks beautiful until spring!

Main Photo Credit: be free | Adobe Stock Free | License

Amanda Shiffler

Most comfortable with soil under her fingernails, Amanda has an enthusiasm for gardening, agriculture, and all things plant-related. With a master's degree in agriculture and more than a decade of experience gardening and tending to her lawn, she combines her plant knowledge and knack for writing to share what she knows and loves.