Benefits of a Winter Fertilizer

What benefits can you expect from a winter fertilizer? Better fall and winter color, improved root growth, less winter damage, earlier and healthier spring green-up, denser shoots, and increased disease resistance.

However, not all grasses benefit the same from a winter fertilizer. For starters, warm-season grasses gain most from a potassium application, while cool-season grasses benefit more from nitrogen. This article discusses all the important details about winter fertilizer benefits.

Winter fertilizers are a type of lawn fertilizers applied in late fall to improve cold hardiness. They can be used as the second fall application when the grass is weak and needs strengthening before the freeze. You’ll also find them in stores labeled as winterizers or winter survival fertilizers.

Most formulas include a balanced mix of nitrogen and potassium (from 2:1 to 1:2, parts of nitrogen to potassium). They have more potassium than regular fertilizers to support stronger tissues and better disease resistance. 

To be effective, winter fertilizers must be applied when the grass has slowed its growth but is still bright green and has not yet entered dormancy. Dormant applications are less practical and can lead to nitrogen leaching into the water table.

Five benefits of winter fertilizers

1. Improved resistance to winter kill

The potassium in winter fertilizers improves drought resilience and cold hardiness, especially in warm-season grasses. This mineral helps the plant build thicker cell walls and tissue and better manage its internal water to avoid moisture loss. With enough potassium, grass is more resistant to desiccation, cold winds, and freezing.

However, this benefit does not apply to all lawns. Applying a fertilizer with potassium is most effective when the soil has a deficit (potassium is under 50-100 parts per million, depending on the soil test). If the ground has enough potassium, adding more does not make the turf stronger or better-looking. 

2. Better color in late fall and early winter

If you want to enjoy a green lawn late into the season, apply winter fertilizers. The light nitrogen boost the late-season fertilizers provide helps cool-season grasses such as perennial ryegrass, Kentucky bluegrass, tall fescue, and fine fescue keep an intense green color until late fall and early winter.

As with potassium, the effect is not the same on all lawns because soil temperature also counts. Late-season nitrogen affects grass color as long as the grass is not yet dormant and still going through photosynthesis. This is why the effect is more pronounced in areas with warmer winters, such as the Mid-Atlantic and transition-zone states. 

3. Faster spring green-up 

Cool-season turf fertilized in late fall is like a marathon runner trained indoors all winter: full of energy and ready to go. Grass plants have carbohydrate reserves in their crowns and roots and additional nitrogen in the soil left from the late fall application. As soon as temperatures are suitable, they pop up from the ground, earlier than with spring fertilization. 

How much earlier? Late fall fertilization can lead the lawn to green up two to six weeks earlier, according to Professor Anthony J. Koski from Colorado State University and Professor John Street from Ohio State University.

And that’s not all. They also come with better roots.

4. Better roots and disease resistance

As an added benefit, spring growth supported by a winter fertilizer is more balanced, with plants investing in top growth but also in root development. That’s different from early spring fertilization, where you’ll mainly see forced growth of stems and leaves to the detriment of the root system.

“It appears that the excessive shoot growth encouraged by early spring nitrogen applications utilizes carbohydrates that may otherwise be used for growing roots,” professors Koski and Street explain.

Better roots make for healthier, more resilient grass that can better withstand spring diseases, summer heat, and drought. Aaron Patton, Turfgrass Extension Specialist at Purdue University, mentions an improved tolerance to spring diseases such as red thread and pink snow mold.

5. No need for an early spring fertilization

If you apply a winter fertilizer late in the fall, when spring arrives, grass plants already have internal reserves and some nitrogen in the soil to help them grow. Experts at Ohio University say these resources are often enough to keep the grass growing until May- June, making early spring fertilization unnecessary.

Related articles:

• “Tips for Spring Lawn Care”
• “Lawn Care Calendar for Cool-Season Grass”
• “Lawn Care Calendar for Warm-Season Grass”

FAQ about winter fertilizer benefits

When is it best to apply a winter fertilizer?

The best time to apply a winter fertilizer is near the last mow of the season but before the first freeze. While the grass no longer grows leaves and shoots, it must still be active, growing roots and storing nutrients for the winterizer to be effective.

What’s the difference between a fall fertilizer and a winter fertilizer?

Both fertilizers are applied in the fall, so winter fertilizers are sometimes called fall fertilizers and vice-versa. The main differences are the time of the application and the nutrient content. Fall fertilizers are applied in early to mid-fall and are slow-release, while winter fertilizers are applied in late fall and are quick-release.

Max out the fertilizer benefits with a pro application!

It takes skill and experience to put the right fertilizer on a lawn at the right time and reap the maximum benefits. Lawn Love pros can do that for you. Find a lawn care professional near you and enjoy the lush, thick lawn of your dreams!

Main Image Credit: Poramet | Adobe Stock Free | License

Sinziana Spiridon

Sinziana Spiridon is an outdoorsy blog writer with a green thumb and a passion for organic gardening. When not writing about weeds, pests, soil, and growing plants, she's tending to her veggie garden and the lovely turf strip in her front yard.

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