How to Winterize Your Lawn

With winter on the way, don’t skip the essentials of lawn winterization. Find out how to winterize your lawn the right way: keep mowing, rake leaves and debris, water, aerate, dethatch, overseed, apply fertilizer and soil amendments, control weeds, control pests, control diseases, maintain your tools, winterize your sprinklers, and remove snow.

How to prepare your lawn for winter

As temperatures drop and grass growth slows, start thinking about winter-proofing your lawn:

1. Time the last mow of the season

Cool-season grasses thrive in fall temperatures of between 60 and 75 degrees Fahrenheit. Reduced heat and higher humidity levels keep them growing vigorously. Once winter arrives, they become semi-dormant and grow very slowly. Warm-season grasses enter complete winter dormancy and stop growing.

The final mow of the season should be:

• Cool-season grasses: Early December when daytime temperatures drop below 40 degrees Fahrenheit.
• Warm-season grasses: Late November when daytime temperatures drop below 50 to 55 degrees Fahrenheit.

Mow your lawn as long as the grass grows and give it a final trim before winter sets in. Try to avoid cutting the grass too short, which can leave it vulnerable in winter. Follow recommended mowing heights when preparing for the cold season.

2. Rake leaves and debris

Fallen leaves and debris can block air and sunlight from reaching your lawn. When they’re wet (either from rain or snow), leaves also invite diseases and pests.

Rake leaves and remove debris at least once a week. Do this in sections to gather leaves into manageable piles. Clear all leaves from your lawn before the first heavy snowfall to keep them from getting trapped underneath. 

Use a good-quality rake or leaf blower for efficient removal. Choose the tools according to the size of your lawn and the amount of debris you have. 

When finished:

• Consider adding the leaves to a compost pile for a boost of nutrients.
• If you own a mulching mower, cut the leaves into smaller pieces and distribute them back onto the lawn to enrich the soil.
• Dispose of the leaves responsibly by checking local leaf collection services.

3. Adjust your watering routine

As winter approaches, adapt your irrigation schedule to meet the changing needs of your lawn. Here’s how:

• Reduce frequency: In winter, lawns need less water because they grow slower (or stop) and lose less moisture. Cut your watering by half or more, aiming for ½ inch per week. If you watered three times a week before, do it once a week now.
• Monitor the weather: Pay attention to rainfall and temperatures. In snowy areas, stop watering by late October or early November. In milder climates, you can water until mid-November or until temperatures consistently drop below 40 degrees Fahrenheit. Always stop watering at least 24 to 48 hours before the first anticipated frost to prevent ice buildup on your grass.
• Time your watering: Just like other times of the year, water in the morning between 5 a.m. and 9 a.m. to allow the moisture to be absorbed before nighttime and reduce the risk of frost damage.
• Adjust run times: If you use an automatic sprinkler system, set it to water for less time. For instance, cut watering from 30 minutes to 15 minutes as winter draws closer. You might even skip watering during long cold and wet spells.
• Check soil moisture: Stick a screwdriver or soil probe into the ground to gauge moisture depth. Water only if the top few inches of soil are dry.
  

4. Aerate and dethatch

If you have cool-season grass, aerate and dethatch in early September. This grass type grows best in the fall, so it can take advantage of improved soil conditions for root development. It also helps the lawn recover from summer heat and prepare for winter. If you have warm-season grass, fall isn’t the best time for these tasks; wait until late spring to early summer.

As you aerate, you create holes in the soil with an aerator to improve air, water, and nutrient circulation. When you dethatch, you remove the thatch layer (dead grass, roots, and other organic material) that builds up between the soil and your lawn.

Aeration and dethatching in the fall can impact the health of your grass come spring. They fix compacted soil, improve soil health, and strengthen roots, helping your grass prepare for winter. 

5. Overseed

After dethatching and aeration, overseed the lawn for a lush carpet in the spring. If you have cool-season grass, fall is the perfect time to overseed. This grass type thrives in cooler temperatures, able to grow vigorously thanks to extra rain that nourishes the roots. Warm-season grass benefits from early summer overseeding, though in milder climates you can adjust that slightly.

For regions with snow and frost: 

• Overseed your cool-season lawn in early fall, around six to eight weeks before the first expected frost. This allows the new grass enough time to establish before the ground freezes. 

For regions with mild winters and little to no snow: 

• Overseed your cool-season lawn in mid to late fall. The milder weather allows the grass to establish without the threat of extreme cold or frost. 
• Warm-season grass usually benefits from overseeding in late spring to early summer, but in areas with mild temperatures, another round in early fall can work just as well. Just make sure soil temperature isn’t below 50 to 55 degrees Fahrenheit (even in mild climates). A soil thermometer can come in handy.

Choose a high-quality grass seed that’s suitable for your region and lawn type. Spread the seed evenly across your lawn, paying extra attention to bare or thin areas. 

Clemson Cooperative Extension says watering is the most important part of growing new grass seed. If it’s not raining enough, water two to three times a day for 10 or 15 minutes. Repeat this for two to three weeks (or as long as needed for germination). 

Then, start watering two or three times a week for about 20 to 30 minutes. You want to reach between 1 and 1 ½ inches of water a week (depending on your grass type and local climate). If you get enough rainfall (as is common in fall), cut back on watering or stop completely. Let the weather guide you.

Pro tip: If you don’t know your sprinkler system output, try the tuna can test.

6. Apply fertilizer and soil amendments

Before winter arrives, choose and apply a fertilizer for the season. Unlike spring or summer fertilizers that offer a balanced mix of nutrients, winter fertilizers (or winterizers) address different nutrient needs:

• They contain lower levels of nitrogen (N) to prevent unnecessary leaf and shoot growth during the cold months.
• They contain higher levels of phosphorus (P) to promote healthy roots, boost nutrient uptake, and help the grass recover quickly after winter.
• They contain higher levels of potassium (K) for strong roots and winter hardiness.
  

Cool-season grasses thrive in the fall and stay somewhat active during winter. Apply fertilizer in early September to late October to help them grow, develop strong roots, and prepare for winter. 

Warm-season grasses typically don’t need fertilizer in the fall, as they enter dormancy naturally when temperatures cool. At this stage, they absorb fewer nutrients and their metabolic activity slows down. Leave fertilizer out to prevent new, tender growth or feed them with potassium and phosphorus to enhance winter hardiness.

Standard winterizer N-P-K formulations look like 10-20-20 or 5-10-20. Select a slow-release product to supply nutrients for your grass all winter long. 

If you can, also incorporate soil amendments like compost or organic matter into your lawn care routine. They improve soil structure, enhance nutrient retention, support beneficial soil organisms, and adjust soil pH if needed.

Pro tip: Before applying fertilizer, conduct a soil test to know what your lawn needs. The soil test report will detail the best fertilizer and amendments for your lawn. Contact your local agricultural extension office to find out how to test your soil. 

7. Control weeds

While winter isn’t a common time for weeds, some annual and perennial weeds can stay dormant and sprout in spring. As such, pre-emergent weed control is vital.

Here’s how to prevent weed growth during the colder months:

• In early fall, apply a pre-emergent herbicide to prevent winter annual weeds. These weed killers create a barrier in the soil, inhibiting seedling growth.
• Lay mulch to block sunlight and prevent weed seeds from establishing.
• On milder winter days, walk around your lawn and remove emerging weeds by hand. Get the entire root to prevent regrowth.
• Mow your lawn regularly to avoid weeds that like to hide in tall grass. Keep the grass at the recommended height.
• Reduce bare or thin areas to crowd out weeds (accomplished through overseeding).

8. Eliminate pests

Pests can still pose a problem in winter, especially in mild climates. 

Prevention is the best way to have a pest-free lawn. In the fall (and the rest of the year), inspect your grass and check for visible signs of pests, such as unusual patches, discoloration, or chewed grass blades. Check spots where pests might hide, like in grass clippings or thatch.

Many pests survive the winter months by hiding in your lawn (also called overwintering). These include:

• Aphids
• Caterpillars
• Chinch bugs
• Cutworms
• Grubs

If you spot signs of pest activity, choose the right treatment based on the pest. Options include:

• Insecticidal soap
• Diatomaceous earth
• Organic pest control including vinegar, essential oils, and vegetable oils
• Chemical insecticides
  

9. Control diseases

Treating summer/fall existing diseases

During summer and fall, your grass may develop brown patch, powdery mildew, dollar spot, red thread, leaf spot, or rust. In such cases, use a targeted fungicide to treat the disease(s) before winter sets in. 

For the best chance at eradicating a disease before the cold season, Michigan State University Extension recommends applying fungicide as soon as you notice signs of infection. Consider its mode of action, especially during the rainy season (as it’s typically the case in fall).

• Systemic: Enters the grass and moves throughout its system, preventing fungal spore germination and inhibiting fungal enzymes needed for growth. It creates a barrier and helps the grass recover once the threat is over.
• Contact: Once applied, it remains on the plant’s surface and kills any fungi that come into direct contact with it. It acts as a shield to stop new infections.

Systemic treatments are more effective and less likely to be washed away by rain.

Preventing new diseases before winter

For prevention, apply fungicide in early to late fall before the first major snowfall or frost (six to eight weeks prior). This allows the treatment to create a shield against new diseases that might appear as the weather changes. 

After application, continue to monitor your lawn for signs of fungal activity. Identify and treat fungal diseases early to protect your lawn.

10. Prepare tools for storage

Give your lawn mower and hand tools some TLC before going into winter storage:

• Clean your equipment to remove dirt, grass clippings, and debris. Use a wire brush, scraper, or compressed air to do it.
• For gas-powered equipment, drain the fuel tanks or add a fuel stabilizer to prevent the gasoline from going stale and clogging the engine. If you’re removing the gas, dispose of it responsibly.
• Make any necessary oil changes. Used oil contains contaminants that can corrode engine components over time.
• Check the mower blades, trimmer lines, and cutting implements. Sharpen or replace them as needed to ensure clean cuts next season.
• Apply lubricants to moving parts, such as bearings and hinges, to prevent rust and ensure smooth operation.
• Store your equipment in a dry, sheltered area like a garage or shed. Cover it with tarps or specialized covers to protect them from dust and moisture.
  

11. Winterize your sprinklers

Get your sprinkler system ready for winter to prevent frost damage. Here’s a helpful checklist:

• Turn off the water supply: Locate the main shut-off valve, typically found in your basement, crawl space, or a valve box in your yard. Turn it clockwise to close the valve and stop the water flow to the system.
• Drain the system: Open all the drain valves and drain plugs on your sprinkler system. This allows any remaining water in the pipes to drain out completely. If your system has automatic drains, activate them to expel all water.
• Release pressure: This prevents damage to valves and pipes. Open the test valves on the backflow preventer (if your system has one) and the manual drain valve at the system’s lowest point.
• Remove filters: If your system includes filters, remove them and store them in a safe, dry place for the winter. Inspect them for any damage or wear and replace them if necessary.
• Protect above-ground components: These include sprinkler heads and valve boxes. Use insulated, waterproof covers or blankets to protect against frost and keep them from freezing and cracking.
• Insulate pipes: Use foam pipe insulation, paying special attention to pipes located near the surface or in areas prone to cold drafts.
• Disconnect hoses and sprinklers: Store everything indoors to avoid damage from freezing.
  

12. Remove snow

If you live in a region that sees snow, remove it regularly to protect your grass from damage. 

Remove thick snow with a snow blower or shovel, avoiding damage to the grass. Direct snow away from the lawn and onto driveways, sidewalks, or other non-turf areas. Large piles of snow can smother the grass and cause poor air circulation. They can also melt unevenly and result in waterlogged spots and fungal diseases.

Continue to do this throughout winter. 

FAQ about how to winterize your lawn

Can I walk on my lawn over winter?

Try to avoid heavy foot traffic on your frozen lawn. While gentle walking is typically fine, avoid walking on snow-covered areas to prevent compaction. 

Can I skip winterizing my lawn in a mild climate?

Winterizing in a mild climate might not be as critical as in regions with cold winters, but it’s still beneficial. It helps your lawn recover from the stress of summer, promotes strong roots, and maintains a healthy lawn.

In temperate areas, opt for:

• Mowing
• Leaf and debris removal
• Aeration
• Fertilization
• Watering

How much does professional sprinkler system winterization cost?

The national average of sprinkler winterization is around $90. Most professionals charge between $60 and $120 to winterize sprinkler systems.

Call in the pros

If winter lawn preparation is too much for your to-do list, let Lawn Love connect you with a pro in your area. They’ll get your lawn winter-ready before Jack Frost starts nipping at your nose and the ground freezes.

Main Photo Credit: Artem Sapegin | Unsplash