Normally, we recommend that you continue mowing during the fall months at about 2.5 inches, then possibly lower the height a little during late fall. Also, one should keep mowing as long as the grass is growing. Never allow the height to reach four or five inches going into the winter.
For our drought-stricken lawns — mow only as necessary to mow the tops off weeds and even up the lawn — but mow as high as you can set your mower — maybe as high as four inches. After soaking rains and recovery begins to occur, maintain the height at about 2.5 inches.
Fall is normally the best time of year to control broadleaf weeds. This is best accomplished with the three-way herbicides that include 2-4-D and when applied during October and early November. However, herbicides will not kill weeds that are suffering from drought and unfortunately the herbicides may damage drought stricken grass like bluegrass and tall fescue. Therefore, wait until the weeds begin growing—possibly two or three weeks after a soaking rain. If the lawn is being renovated with new seed, broadleaf weed control may need to be delayed until next spring. Herbicides applied a couple of weeks before seed germination or applied a couple of weeks after germination will reduce establishment.
Fall is the best time of year to fertilize with nitrogen and our normal recommendation is to make two applications in late October through December, approximately four to six weeks apart. Begin applying nitrogen fertilizer, even if some reseeding is needed. We often find that rapid regrowth following a nitrogen application is much more important in filling-in an injured turf than waiting for seed germination and seedling growth.
But be sure when you fertilize late in the fall that you keep mowing as long as the grass is growing. Sometimes that requires a mowing or two in December, if we have a mild fall. Applications of nitrogen made while the lawn remains drought stricken is not recommended. This nitrogen may further increase the stress upon the turf and it is more likely to feed the weeds than feed the turf since many weed species remain green and ready for rapid growth such as crabgrass. Other nutrients such as phosphate, potash and lime may be applied. Drought stricken lawns will probably benefit from some seeding/renovation. But never just broadcast the seed on the surface and expect to get establishment. Some soil preparation is necessary to get good soil-seed contact. Most people can effectively use dethatchers, no-till seeders and possibly aerifiers to improve the soil seed contact. Without irrigation, there is no need attempting to seed until we get a soaking rain. I do not suggest seeding from about Oct. 15 through November. Drought stricken lawns still have a chance to recover. If we can get a good soaking rain, we still have about two good months of growing weather this year.
For more information, please contact Dan Grigson, U.K. Extension Agent at the Lincoln County Extension Office, 104 Metker Trail, Stanford, 365-2447.