Important lawn care in the autumn

Did you know that north­ern grasses have two growth peri­ods a year? All grasses begin to grow in the spring when the soil warms, but blue­grass, rye­grass, and var­i­ous fes­cues get a head start on their south­ern cousins. They grow for a few months in the spring, until it gets really hot. And then, to pro­tect them­selves from the heat, they slow down or stop grow­ing alto­gether. In warm years, that just means you don’t mow as much. In hot years, the whole lawn may be brown.

The sec­ond period of growth is the autumn. When the tem­per­a­tures drop and the rain, fog and dew pro­vide plenty of ambi­ent mois­ture, grass greens up and starts grow­ing again. The fall growth spurt isn’t as fast as the spring one, but it is cru­cial. Instead of putting all its energy into grow­ing blades of grass, much of the energy pro­duced will be stored in the crowns of the grass to pre­pare for win­ter dormancy.

Because the autumn growth is a period of energy stor­age, now is the most impor­tant time to fer­til­ize a lawn. If you can only spread fer­til­izer once a year, early autumn is the time to do it. The grass will ben­e­fit imme­di­ately, but it will also store the nutri­ents for use next spring. After a long, hot sum­mer like this has been, the grass will have expe­ri­enced enor­mous stress. If you want to learn more about how to fer­til­ize, visit ohioline.osu.edu/hyg-fact/4000/4006.html.

If you have a thick layer of woody, dead mate­r­ial between the green of your lawn and the ground, you may be hav­ing issues with thatch. A thin layer of thatch is nor­mal in any lawn, but if the layer gets too thick it can begin to cause prob­lems. If you have more than half an inch of thatch, one of the best ways to reduce the amount of thatch and improve the soil is called core aer­a­tion. This process pulls plugs of soil out and lays them on top of the lawn. This improves the drainage of the lawn and encour­ages the thatch layer to break down more effec­tively. If you’re con­sid­er­ing aer­a­tion, fall is a great time. For more infor­ma­tion on thatch, visit ohioline.osu.edu/hyg-fact/4000/4008.html.

Fall is also ideal for seed­ing cool-season grasses. The soil is still warm from the sum­mer, but the air tends to be cool and moist. This makes it eas­ier to cre­ate a seed bed that can stay con­sis­tently moist, but not too wet or too dry. Warmer soil tem­per­a­tures will lead to faster seed ger­mi­na­tion. Once it ger­mi­nates, grass needs about a month of good grow­ing weather to get estab­lished so that it can sur­vive the win­ter. In Delaware County, any seed­ing project is best done in the month of September.

The tem­per­a­tures this sum­mer were so high, for so long, and water was scarce. Much of our region had water­ing restric­tions. This means that there are areas in many lawns that might not fully recover. If the areas that have not become green are larger than four inches across, it may be more prac­ti­cal to rake out the dead grass and re-seed the area. If the area is smaller, many vari­eties of cool-season grass, espe­cially Ken­tucky blue­grass, will fill in the bare area. For more infor­ma­tion about seed­ing a lawn, visit ohioline.osu.edu/b546/b546_6.html

DATE CANCELLATION

The edu­ca­tional series sched­uled to be held Sept. 20 at the YMCA has been can­celled. Please mark your cal­en­dars for Oct. 18 for the final ses­sion of the gar­den­ing series. Thank you for sup­port­ing our programs.

Wendy Wolpert is a Delaware County OSU Exten­sion Mas­ter Gar­dener volunteer.

Posted by Master Gardener on Sep 7 2012. You can follow any responses to this entry through the RSS Feed. Comments can be made below.