Fertilizing cool-season lawns after they’ve gone dormant promotes quicker recovery, improved disease resistance, and an earlier green-up in the spring.

Choosing the Right Fertilizer

Before we cover application guidelines, it’s important to know what fertilizers work best for dormant fertilization. There are a few standout options available at ATS.

Nature Safe 8-3-5 is an excellent organic fertilizer. It is a slow-release product that is less soluble than traditional fertilizers, allowing the soil to hold more nutrients (via an increased cation exchange capacity) and boosting the soil’s water-holding capacity. These two factors will help customers’ lawns hold onto nutrients more effectively in the winter and thrive as they come out of dormancy.

An all-mineral fertilizer like Advanced Turf 34-0-4 will also be effective. This product does not contain slow-release nitrogen, but that is unnecessary since the urea in the fertilizer depends on microbial activity for plant-available nutrition. In addition to nitrogen, 34-0-4 contains potassium, which will help your customers’ turf store carbohydrates and improve cell wall turgidity.

Why Organic Fertilizers are Ideal for Dormant Fertilization

One of the biggest benefits of organic fertilizers is that they rely on microbial activity for nutrient uptake. This means that your product of choice will be effective until soil temperatures drop below 40°F, which is the temperature at which microbial activity ceases. During the winter, an organic fertilizer’s slow-release properties will keep the already-distributed nutrients in the root zone, letting the turf absorb them as needed.

Organic fertilizers will also enable the turf to build up carbohydrate reserves, which will be used to strengthen the plants’ cell walls and cuticles. This will help lawns survive the winter, recover easily, and ward off disease in the spring. Once the soil warms back up to 40°F, nutrient uptake will resume, allowing for an early green-up.

Timing Your Dormant Fertilizer Application

Timing is critical for dormant fertilization. Applications should be made after top growth has stopped but before the ground freezes. This gives lawn care operators between Halloween and Thanksgiving to put down their fertilizer.

When fertilizer is put down on frozen soil, water contamination due to runoff is possible. To ensure your customers’ soil isn’t frozen, insert a screwdriver four to six inches into the ground. If it goes in smoothly, you can still make an application.

If you dormant seed a customer’s property, don’t dormant fertilize. Instead, wait until the seeds germinate in the early spring and then apply a starter fertilizer.

To learn more about dormant fertilization and how it can help your customers’ lawns bounce back stronger in the spring, reach out to your ATS rep.