Winterizing fertilizer is used for certain turf types at the end of the growing season each year. It’s important to know not only when to winterize your lawn, but also what kind of fertilizer to apply. Certain types of lawns need a certain balance of nutrients at certain times of the year. For example, a fescue fertilizer program is going to be different from one designed for zoysia. This is why it’s important to do your due diligence before applying nutrients to your lawn.

For a warm season lawn, winterizing fertilizer is unnecessary because the turf goes fully dormant for the winter and is using a minimal amount of nutrients to stay alive. This is why they turn a light brown color once it gets cold outside. However, cool season grasses like fescue and bluegrass don’t go completely dormant in winter. They may lose some of their color and stop growing vertically, but below ground and on a cellular level, there is usually a lot of development going on.

Winter is generally when your cool season turf plants do the most root development and cell wall hardening. Vertical growth is stressful and associated with competition, aggressive photosynthesis, and reproduction. These are all natural processes that your fescue wants to do when it’s warm outside, but once it gets cold, your lawn would rather hunker down and turn inward.

Nutritionally speaking, the macronutrient most associated with this winter development for your turf is potassium. Potassium gives something to every part of a grass plant. It helps build a stronger cell wall both in the leafy part of the plant as well in the root. This is vital during the winter when deep freezes can do damage to unhealthy growth. Additionally, phosphorus helps encourage better root development, while nitrogen helps the lawn keep some of its warm season color.

These nutritional needs that vary throughout the year are why it is so important to know what kind of fertilizer is best for the season as well as when to winterize your lawn. Typically, the best fescue fertilizer to act as a winterizing fertilizer is going to be one with all three macronutrients, but also with a stronger ratio promoting a potassium load in your soil system. Keep in mind, every region has different climates as well as different soil conditions. It is important to perform a soil test regularly to identify which nutrients are most in need of supplementation.

Generally, a balanced fertilizer program will introduce phosphorus into the soil system only if the macronutrient is generally lacking in the soil to begin with. This is best done just before or at the same time as the fall seeding because it makes the phosphorus available for absorption as soon as the seed germinates. The most important part of fescue seedling development is deep and complex root systems. The stronger the roots are by the time summer rolls around, the better the lawn will be able to survive the stresses of heat and drought.

When appropriate based on the type of lawn being cultivated and the nutrients already existing in the yard’s soil system, a winterizing fertilizer can be one of the most important treatments in a year round turf management program. For the greatest success, it should be done just as the lawn begins to enter its winter dormancy and should focus on potassium balanced with other key nutrients. If you are interested in learning more about the Picture Perfect Program, be sure to check out our other related blog articles.