Now is the right time to start proper care on your lawn.
The best way to prevent problems in your lawn is to maintain a dense stand of turf that is mowed at the correct height for that variety. The dense vegetative growth will prevent weeds from coming up and competing with grass.
Mowing at the proper height will reduce stress on plants and provide the best chance for dense growth by allowing roots to grow deeper into the soil. Deep roots are better able to find a source of water when needed.
The best way to encourage weeds is to mow grass too short and scalp it or to allow too much time to pass between mowing. Because weeds are usually undesired, never remove more than 1/3 of the turfgrass blade when mowing.
If you do fall behind then raise your mow height and slowly move the height back down over several weeks. If you remove over 30% of the blade then you weaken the plant causing poorer root growth and possible disease introduction. If plants are cut too short plants will have less leaf blade surface for energy production. Your home yard is not a golf course and should not be maintained as such.
Wet weather and dry weather can be equally harmful to a healthy, dense lawn. If you mow when grass is wet you will create large clumps of grass that will lead to deterioration in plants. You may also create ruts in the lawn and compact soil in areas causing root stress.
It is better to wait, increase the mow height and work your way back down to the height you want your grass to be.
Depending on the type of turf in your yard, dry periods of weather can also cause severe stress to your plants. Cool season grass will not grow as aggressively during the dry periods of summer or anytime when water has become scarce.
During these times it is best to space your mowing schedule further apart to limit damage that may be caused from driving over a drought stressed lawn. Mow early in the morning or later in the evening when the heat of the day is not a factor.
General mowing heights for cool season turf by type include: Kentucky bluegrass -- mow 2.5 to 3.5 inches, Tall fescue -- mow 3.0 to 4.0 inches, Fescue/ bluegrass -- mow 3.0 to 3.5 inches, Bluegrass/ ryegrass -- mow 2.5 to 3.5 inches and Creeping red fescue -- mow 3.0 to 3.5 inches. General mowing heights for warm season turf are Zoysia -- mow 1.5 to 2.0 inches, Bermudagrass - mow 1.5 to 2.0 inches and Buffalograss - mow 2.5 to 4.0 inches.
When dealing with turf disease, prevention can go a long way toward reducing the presence of disease. It is important to know what conditions each disease prefers and what type of turf each disease prefers. Below is a list of common diseases and their growing conditions.
Brown patch -- high nitrogen, hot / humid weather (fescue, ryegrass and bermuda)
Rust -- hot, dry periods when grass grows slow (bluegrass, ryegrass and fescue)
Summer patch -- hot weather with rainfall in July and August, excess nitrogen (bluegrass)
Pythium -- hot weather after a storm, high nitrogen soil (ryegrass or bluegrass and fescue)
Dollar Spot -- warm day / cool night, low nitrogen (bluegrass, ryegrass, fine fescue and bermuda)
Large Brown Patch -- during cooler spring and fall weather (zoysia)
Fertility is also an important cultural practice that can help prevent disease and maintain a healthy stand of turf. Fertilizer can be applied in fall or early spring for cool season grasses and during active growth for warm season grass beginning as they green up. This will give the grass a boost and help to create a dense, healthy stand of turf that is better equipped to fight disease.
One final maintenance requirement for healthy turf is thatch control. Thatch can build up as dead and living plant material increases between the soil and living grass plant.
This area is a great place for disease organisms to wait for the proper conditions to infect turf. Thatch should be removed in the spring or fall for cool season grass and in midsummer for warm season grass. This layer should never accumulate beyond ? inch of material.
Helpful Resource: Fresenburg, Brad. "Reducing Risk of Turfgrass Diseases." and "Proper Mowing Practices for Your Lawn." Missouri Environment and Garden April 2010 Volume 16, Number 4: page 27-31; Turf Disease Control. Brad Fresenburg. University of Missouri. Extension Publication G6756. Rev. January 2006.
The Extension office is located in Kennett, Missouri at 101 South Main Street (the old bank) on the 2nd floor. Open Monday -- Friday. University of Missouri Extension programs are open to all.
Sarah Denkler is a horticulture specialist
with University of Missouri Extension
in Dunklin County.