The Basics of Fall Fertilization
It is well-known that fertilization can help grass thrive instead of just survive, but as for when you should feed a lawn depends on several factors.
Fertilization is most beneficial when applied before a period of active growth. It is best to apply fertilizer in the spring and fall for cool-season grasses.
Fall fertilization has several benefits over spring fertilization for cool-season grasses. Lawns fertilized in the fall have earlier green-up in the spring without addition shoot growth, reducing the likelihood of summer diseases. It also allows the lawn to have an additional green period in the fall.
“A fall feeding for cool-season grasses is recommended to promote the growth the grass will need to sustain itself during the winter,” writes David Mellor, Fenway Park’s master groundskeeper. “It will encourage a longer growing season, which will help the grass store up carbohydrates for a quick green up in the spring.”
Soil Tests Even if your lawn appears green and healthy, it’s a good rule of thumb to have the soil tested every two to three years, as conditions may change. Soil samples should be around six inches deep and collected from 8 – 10 locations throughout the yard. These can be sent off to a facility for testing.
A soil test will reveal the soil’s pH, which can affect soil nutrient availability, along with what nutrients are lacking and which are adequate. Soil tests can inform you how much phosphorus and potassium the soil needs, but there is no reliable test for how much nitrogen is needed due to its mobility within the soil.
Needed Nutrients A healthy lawn needs numerous elements to do well but thankfully the majority are micronutrients that are not needed in large quantities. The macronutrients such as nitrogen, phosphorous, and potassium are the main ones to focus on.
Nitrogen plays an integral part in helping keep the grass green and encouraging shoot growth. Slow-release nitrogen is advised for fall fertilization to ensure uniform growth over a long period of time while reducing the chance of burning.