Fall lawn fertilization important

Q. I just overseeded my lawn. If I put down fertilizer, will it keep the grass seeds from sprouting?”

Frank from Struthers

A. No Frank, your fertilizer application will not stop the grass seeds from germinating (sprouting). The confusion most likely comes from common fertilizer applications in the spring that are mixed with a pre-emergent herbicide. Fall-applied products should contain nutrients only.

Pre-emergent herbicides are chemicals that prevent weed seeds from germinating in establish lawns. These chemicals are usually put down in the spring. A pre-emergent will stop week seeds, grass seeds or another seedfrom germinating for several weeks after application.

Fall is a good time to fertilize the cool-season grasses typically found in our area because the nutrients will go primarily to support root growth. They help the grass plants build up reserves to get through the winter and green up healthfully in spring. That’s because top growth stops in fall after about 10 days with average daily temperatures below 50F. But roots will continue to grow and take up fertilizer until the ground freezes.

If you haven’t done so, I would recommend having your lawn soil- tested before applying fertilizer. A soil test will tell you what nutrients to add to your lawn and in what amounts. The Extension does analysis tests for $20. For more information, call our office at 330 533-5538 or visit http://go.osu.edu/soiltesting.

Fall and late fall lawn fertilization is much more important than spring and summer fertilization. Following recommendations for fertilizing this time of year will do you more good than any other time of year. Remember – the amount of fertilizer is very small. Overapplication is never a good idea. Many fertilizer formulations need only 2 pounds of total product per 1,000 square feet of lawn. Find our recommendations for commercial and organic fertilizer at http://go.osu.edu/fallfertilizer.

Today’s answer was provided by David Sprague, OSU Extension master gardener volunteer. Call the office hot line at 330-533-5538 to submit your questions. Clinic hours are Mondays and Thursdays from 9 a.m. to noon through October.