Dear Aggie: Now that spring is here, when should I fertilize my lawn?
Actually, the best time to apply fertilizers to your lawn is in the fall. This may seem counterintuitive because we always think in terms of the spring season for many lawn tasks, plus we are swayed by advertising that encourages us to use lawn care products with abandon. One fall application of fertilizer is all that is needed for most lawns. Over-fertilization of turf can cause many problems, not to mention the consequences of putting fertilizers into the environment when they are not needed. Based on the way that turf grasses grow it is best to wait until fall for several reasons:
1. Spring applications will cause the grass to grow quickly due to the nitrogen in the fertilizer. You think you are mowing a lot now? Spring fertilization will lead to more mowing.
2. This rapid growth will occur at the expense of the root system. The roots won’t be able to keep up with the with the extensive top growth. This will cause an earlier and longer period of summer dormancy (brown out).
3. Home turf that is fertilized more than once per year will be more susceptible to disease and insect pests.
4. When fertilizer is applied in the fall the turf will pull the nutrients into the roots where they will be stored until spring. This translates into a faster spring green-up and stronger root system.
In the turf world we like to say “focus on fall.” Lawn fertilizer should be applied around Halloween, or two weeks after your last mowing at a rate of 1 pound of nitrogen per 1,000 square feet. Do not fertilize during “Indian Summer” periods — this will cause excessive top growth and more winter kill. Wait until top growth stops which is usually after about 10 days of temperatures below 50 degrees. After spreading the fertilizer, water your lawn so that the material is moved into the ground where it can be used by the grass. Another option is to spread the fertilizer right before a rain shower.
You will save money and time by fertilizing at the optimum time which is based on how northern turfgrasses grow and not based on selling you a product.
Access the online publication ‘Home Lawn Care Without Pesticides’ at wdt.me/lawns.