Another growing season has come and gone. For us cool season lawn care enthusiasts, the past seven months have flown by and it’s time to put our lawns away for a long winter’s nap.
So with your nitrogen blitz underway and Halloween and Thanksgiving fast approaching, you’re probably asking yourself, how do I prepare my lawn for winter? When do I apply a winter fertilizer? How much winter fertilizer? And what type of fertilizer? After your fall renovations and overseedings are complete, follow these very important late fall lawn care tips to ensure your grass is well prepared for the long winter months ahead.
Clean the lawn
Don’t leave leaves and debris on your lawn over winter. I made this mistake my rookie year and woke up in April to snow mold galore (more on this below). Not to mention the extra spring clean-up needed, when all I wanted to go was to get mowing and throwing down.
Removed as much leaves, sticks and debris as possible. I personally don’t recommend mulching and leaving leaves on the ground over winter – bag them up and recycle in your compost pile.
Lower the height of cut (HOC)
The final cut of the season should be 1-2″ lower than your normal height. Depending on Mother Nature, this is usually in mid to late November. I aim for 2-2.5 inches for the final mow.
As always, take the height down gradually. Leaving the grass taller, like your normal everyday mowing height in May, can keep your grass greener throughout the winter. However, taller grass can also be more susceptible to snow mold and other funguses in the spring.
A clean lawn and a shorter cut will set you up for both winter survival, and early spring lawn success.
Snow Mold – Fungicides
Snow mold generally occurs in the early spring when the snow has melted, soil and outdoor temps begin to get warmer, and grass starts to green up. Snow mold happens when the grass freezes and thaws throughout the winter. Longer grass that has a tendency to flop over onto itself and become matted is also prime turf for fungus. And as previously mentioned, leaves that smother the grass can also cause snow mold.
By taking proper clean up can help prevent snow mold. You can also apply a lawn fungicide like Propiconazole 14.3 just prior to the hard frost. And as temperatures begin to increase enough to start melting the snow (around February here in Massachusetts for example) you can apply another round. The idea is to get it down between the thaw and refreeze, which can be a small window of opportunity.
The best time to apply your winter fertilizer application is going to be before the ground freezes, and after the last final mow of the year. We want to add some Nitrogen (N) to the lawn to provide benefits next year. The Nitrogen that’s applied in the late fall will help green up your lawn in the spring when soil temps begin to approach 50-55 degrees. However, too much Nitrogen applied late in the season promotes more top growth in the lawn – this is a time where the cool season grasses become dormant. This excessive “winter” growth will foster spring diseases, like red thread and snow mold.
Potassium (K), is an essential “all around” vitamin for the grass. Potassium helps it ward-off diseases during cold, harsh winters, and helps the lawns absorb more nutrients in the soil. Grasses use potassium to effectively make proteins and starches to store for the winter.
The Macro-Micro Blend by Yard Mastery is a very good option. Using the Nitrogen Calculator, the 24-4-8 formulation will cover 6,500 sq. ft. and deliver ~0.75 pounds of N per 1,000 ft², and plenty of K. ProPEAT 17-0-4 is an affordable option, as the 17% Nitrogen will deliver 0.68 lbs. of N while covering 10,000 sq. ft. at that rate. Your lawn will wake up and bounce back faster in the spring. Use our Lawn Fertilizer Calculator to help calculate.
If you have low soil pH, and skipped lime in September, apply that now. Any lime will do though I prefer Jonathan Green Mag-I-Cal Plus.
Winter Lawn Care Wrap-up
- Clean the lawn of leaves and debris
- Bag your clippings
- Lower the HOC
- Final mow of the season: 2-2.5″
- Apply a winter fertilizer
- Apply fungicide like Propiconazole 14.3 (optional)
- Limit foot traffic on frozen lawns
- Use a calcium chloride snow/ice melter on walkways near grass and plants
Preparing Your Lawn for Winter FAQs
The best time to apply winter fertilizer on your lawn is in late fall, between your last mowing of the season and before the ground freezes. In New England, this is generally the first 1-2 weeks of November.
As the outside and soil temperatures get colder, the grass will become dormant. Just before the ground becomes frozen, apply your winter fertilizer. The nitrogen will to get into the soil and will be utilized next spring. This fertilizer will help kickstart your lawn in early spring, providing a quicker green-up.
The best fertilizer to apply for your winter fertilizer application is one with mostly fast release nitrogen (N) and some potassium (K). A fertilizer with a 10-0-20 ratio will provide plenty of K, but not a lot of N (about 1/3 lbs. per 1,000 sq. ft.). A 20-0-5 is another popular choice as it will provide some K, but more N (around 3/4 lbs. per 1,000 sq. ft.)
You should apply a full pound of nitrogen per 1,000 sq. ft. Example, if you have a 5,000 sq. ft. lawn and choose a 20-0-5 fertilizer, you would need 25 lbs. to deliver 1 lb. of N per 1,000 sq. ft. to cover your total area.
A final fertilizer application of nitrogen and potassium in the winter can kickstart your lawn the following spring. The nitrogen applied late in the season is stored in the soil overwinter and utilized in the spring as outside and soil temps rise. It helps promote greening, growing, and thickening faster in the spring than if you skipped winter fertilizer. This winter fertilizer application is often considered the most important feeding of the season.