Lawn Care: Different Lawn Diseases
Garden and Lawn Diseases and Treatments
Trying to achieve that picture perfect lawn requires much work, time and patience. It also helps to know what types of diseases that may affect your attainment of the goal. Here are some of the most frequently occurring lawn diseases and some recommended remedies:
This lawn disease is is also known as "winter scald" or fusarium patch; it propagates while snow is covering the lawn. Once the snow melts, patches of dense, cotton-like growth show the presence of the disease. It is generally more severe on lawns in low-lying areas, particularly when large piles of snow have blanketed the grass for long periods. Most lawns will recover from snow mold without treatment when the grass dries and the ground warms; nevertheless, severe cases might kill grass. You can lessen the susceptibility of your lawn to this disease by fertilizing the grass not later than September (late fertilizing makes lawns more susceptible), by keeping the lawn well mowed, and by keeping leaves and other ground coverings off the lawn prior to the covering of snow. Likewise, refrain from piling heavy accumulations of snow on the lawn. If the grass doesn't recover by early summer, excavate the surface using an iron-tooth rake and reseed.
"Going Out" Disease
This generally hits bluegrass, shows itself through the yellowing and thinning of grass during April and May. Actidione, plus sunny weather, arrests it.
Fading Out Disease
This is also known as black mold, develops off-color, yellow-green patches on the grass. A white cloth rubbed over the grass will exhibit sooty black smudges. Actidione or Captan applied according to manufacturer's directions will cure it.
This is also known as summer blight, which happens when night temperatures stay above 70 degrees F. and when the relative humidity gets to 100 percent and shows itself with circular rings on the lawn resembling smoke rings. The remedy is the same as for fading out disease.
Brown circular patches, at least the size of a silver dollar, appear on the lawn during cool, wet periods in spring, summer, or fall. Cobweb like growths appear each time there is dew. Tiny yellow spots on the grass blades become bleached or off-white soon after. Cadmium preparations help.
The disease kills grass by striking at the roots and crowns, is called helminthosporium and cunularia, and results in brown discoloration of grass which is often mistakenly blamed on drought or wrong nutrition. Loosen surface, take out debris. Dust using Captan and reseed.
White "powder" on grass signifies mildew, and in some cases it's so bad you can in fact see it fly in tile air once you touch the grass. Merion bluegrass is extremely susceptible to mildew, as are Windsor, Fylking, and Pennstar. Resistant kinds include Nugget, Delta, Park, and Newport. In shaded off areas, plant fescue (creeping red) and rough bluegrass (Poa trivialis). Both grasses are not simply resistant to mildew, but much more shade-tolerant than Kentucky bluegrass. Chemical control is barely effective unless you use frequent applications. The best solution is to employ resistant varieties of bluegrass.
Red coloring on grass means rust. Since it takes the rust a few days to infect and form reddish pustules on the grass foliage, it is most prevailing on the older leaves—the very ones which would be exposed after mowing. Don't worry about it, as the disease often disappears as the season wanes. Certain fungicides like Actidione or Zineb will check it, but it may not be worth the effort.