Guest blog post from The Lawn Institute.
Cool Season Grasses
Late fall is the best time to prepare your lawn for the coming of winter and at the same time give it a great boost for next spring. Cool season grasses such as Kentucky Bluegrass, Fine Fescue, Perennial Ryegrass, Tall Fescue, Buffalograss and Creeping Bentgrass can all use a little fall prep.
Clean off any debris: Rake leaves and remove any other debris that can block sunlight and limit photosynthesis.
Get a soil test: Assessing your soil health in the fall gives you time to correct nutrient deficiencies and apply the appropriate fertilizer.
Dethatching: Thatch is an accumulation of undecayed and decaying plant matter at the soil surface that can deny grass roots the air, water, and nutrients they need to thrive. Dethatching will increase organic matter and stimulate the soil microbes that consume thatch. (Thatching, by the way, is caused by excess fertilizing, not by mulching grass clippings.)
Aeration: Early to mid-fall is usually a good time to aerate your lawn. The ground is usually soft enough in the fall for removing plugs. Aerating when the ground is too soft from rain (such as in the spring) can sometimes result in holes that close too quickly for nutrients, water, air and fertilizer to reach the root zone. Although aeration is recommended in spring or fall, the latter may be preferred depending on the climate in your area.
Mowing: For the final mowing of the season, cut cool-season grasses to 2½ inches.
Overseeding: Lawns composed of cool season grasses can also profit from overseeding to fix bare patches. Because aeration creates additional space in the soil and reduces compaction, it is a good idea to overseed after aerating. Fall is the best time for overseeding because there is plenty of rain to help the new seed come in with little effort and without spring weeds.
Fertilization: Fall is the number one time to fertilize cool season species so the plants can develop a strong reserve of carbohydrates in their roots. This will aid in spring green-up. Depending on your location, a late fall follow-up application may be needed as well. Apply 1 pound of nitrogen per 1,000 square feet of lawn. Or purchase a product that has a low middle number for NPK (Nitrogen, Phosphorus and Potassium).
Water: Fall lawn care for cool season grasses includes ensuring that your lawn receives enough water to carry it through the winter. Don’t think you can totally forget about watering your lawn during autumn’s dry spells.
Warm Season Grasses
In the southern states, fall is overseeding season as the warm season species go dormant and yellow all winter. Warm-season turfgrasses such as bermudagrass, zoysiagrass, St. Augustine and Centipedegrass will go dormant after the first killing frost.
Avoid fertilizing a warm season turfgrass in the autumn. The latter undergoes a hardening-off process during this time of year to prepare it for winter. Fertilizing warm season grasses in the fall may interfere with that hardening-off process.
The following steps can benefit your lawn next spring.
Get a soil test: Assessing your soil health in the fall gives you time to correct nutrient deficiencies and pH problems before spring.
Throw off thatch: Compacted soil and too much thatch—an accumulation of undecayed and decaying plant matter at the soil surface—can deny grass roots the air, water, and nutrients they need to thrive. (Thatching, by the way, is caused by excess fertilizing, not by mulching grass clippings.) Increasing organic matter will stimulate the soil microbes that consume thatch. If the problem is so bad that water cannot penetrate the thatch, remove the thatch now with a stiff rake or thatching rake.
Mowing: Continue to mow grass until it stops actively growing. For the final mowing of the season, cut warm-season grasses between 1½ and 2 inches, which is just a little shorter than you should cut it during the spring and early autumn.
No fertilization: Don’t fertilize warm-season grasses in fall.
Overseeding: A unique aspect of warm-season turfgrass management is the often used practice of overseeding with ryegrass to provide winter color and an actively growing playing surface for sporting venues. Perennial ryegrass and annual ryegrass are the major cool-season grasses used for this form of “overseeding.” In general, bermudagrass tolerates winter overseeding to a greater degree than zoysiagrass, centipedegrass, or St. Augustine grass.
By overseeding with annual winter ryegrass, homeowners whose lawns are composed of warm season grasses can enjoy a green carpet during the winter, instead of having to look at a brown lawn. But when you buy the seed, be sure to ask for the annual, not the perennial. Annual winter ryegrass will die back when summer’s heat returns, turning over the lawn once again to the warm season grasses. This exit is a timely one. The problem with the perennial winter ryegrass is that it doesn’t go away, competing with your warm season grasses for sunlight, water and nutrients.
For more information about lawn care visit The Lawn Institute at http://www.thelawninstitute.org/
Photo courtesy of The Lawn Institute.