University of Minnesota Extension, Stearns County News
August 20, 2014
Source: Beth Berlin, Extension Educator-Horticulture
University of Minnesota Extension
Stearns & Benton Counties
Fall Lawn Care
By Beth Berlin, University of Minnesota Extension
ST. CLOUD, Minn. (8/20/14) — Are parts of your lawn more weeds that turf grass? Mid-August into Mid-September is the perfect time to reseed and establish a new lawn. This period of the late summer provides favorable conditions for germination and growth. Another advantage is that fewer weed seeds are germinating that end up being competition for resources with the grass seedlings. Plus there is still plenty of time for the plants to be well established before winter.
Proper seed selection is an important first step. In general all grass is sun-loving; however there are certain species and varieties that seem to do better in more shaded conditions, fine fescues seem to tolerate more shade. In areas with a lot of shade, no grass will ever establish well and the homeowner should consider planting other plant species that do well in shade, or possibly thin the canopy of the trees to provide more sunlight to reach the turf. Purchase high quality seed for better results.
Complete proper site preparation by killing off existing weeds or undesired lawn, cultivate and level the soil, and spread seeds. Spreading seeds should be done in two steps at a half application rate, spread in perpendicular directions across the area to provide more uniform coverage. Follow up with light raking, and use a roller to ensure good seed-to-soil contact. Finally water, for best results there should be moist soil to the depth of 4-6 inches. After seeding continue to water as needed; gradually taper off watering as the plants grow and the temperatures cool. New lawns take a while to become mature and established. Nearly a full season is needed for the turf to become durable and capable of handling traffic.
Contrary to what many homeowners have practiced for decades, the best time to fertilize your lawn isn’t spring, but rather late summer and fall. Benefits from applying lawn fertilizers in fall rather than early spring include: 1) Lengthening the period of green in the fall allowing for more photosynthesis and storage of essential carbohydrates, 2) Earlier green-up in the spring without stimulating excessive shoot growth, 3) Allowing the Carbohydrate reserves to remain higher in the spring and summer period, and 4) Reduced incidence of summer diseases.
In order to maximize nitrogen absorption, University of Minnesota Extension recommends that homeowners or turfgrass managers should: 1) Make all fertilizer applications before mid-October, 2) Combine quick-release and slow-release nitrogen sources when applying rates above 0.5 pounds of nitrogen per 1000 square feet, 3) Be aware of temperature and precipitation impacts on your fertilizer applications. Ideal conditions for fertilizer application include a cool day with a good rainfall or watering immediately following to wash the fertilizer off the leaves and into the soil.
Read the fertilizer bag thoroughly before purchasing to ensure you are buying slow-release rather than all quick-release fertilizer. Excess fertilizer in general can lead to wasted financial input, contributing to an influx of nutrients in the environment, and burning and harming the desired grass plants if applied at too high of a rate.
Soil testing should be done to determine nutrient concentration. Factors such as having an irrigated lawn, whether or not clippings are removed, and species of turf all play a role into how much nitrogen fertilizer should be used. Typically leaving grass clippings on the lawn leaves about 1 pound of nitrogen per 1000 square feet per year.
To obtain healthy turfgrass, changing some old habits may be necessary. For more information on lawns visit www.turf.umn.edu