I am sure that the next time there is an educational tour about lawn care in northern Minnesota that my lawn will be a featured stop used to identify every kind of lawn weed that plagues our lawns. But please let me offer some advice on the best time of year to plant lawn grass.
The University of Minnesota says that mid-August to mid-September is the best time to plant lawn grass seed. Up here in plant hardiness zone 3, I think we should adjust for the shorter growing season and say that the whole month of August is the best time to plant lawn grass in this area.
The primary advantage of late season planting is that there will be less competition with weeds. Weeds are genetically programmed to germinate in the spring when the plant has a chance to produce more nasty seeds.
A mixture of grass seed varieties is recommended. Kentucky Bluegrass is great because it has underground stems called rhizomes which allow the grass to spread into damaged areas of lawn. The problem with Kentucky bluegrass is that its germination time at 14 to 30 days may exceed the patience of the homeowner. Rye grasses germinate quickly in 5 to 10 days which is encouraging to seed planters. Ryegrass is a bunch grass so it needs to planted close enough together so the bunches merge with each other. Choose mixes that include perennial ryegrass because annual ryegrass, found in some seed mixes will not grow again next year. Fescues fall in between at seven to 14 days of germination. Fescue is good for shade tolerance and droughty or sandy soils.
Follow the recommendations on the seed bag. Many bags of seed have material to aid germination like water enhancers which may make up a large percentage of the contents. The cheapest seed may not be the best buy if it has lower seed germination or percentage of seed.
For seedbed preparation, start with a soil test. Cultivate the recommended nutrients into the soil. The soil surface should be smooth and free from rocks or clods before planting. Good seed-to-soil contact is important.
Drop seeders are more accurate than broadcast seeders so use one of these if you have a small plot on even ground. Divide your seed in half and apply them in different directions to ensure good coverage. Broadcast seeders will disperse heavier seed further than lights seeds.
Go easy on the fertilizer. Young plants can not handle much fertilizer. Weed and feed fertilizers, if you use them, can wait until next year after the lawn is growing again.
Water to a depth of four to six inches to begin with and then maintain soil moisture throughout the germination process, which may mean watering two or three times a day. Water as deep as the roots have grown.
Applying sod is a good option for establishing a quick lawn. Sod will almost always be Kentucky bluegrass because it holds together with the rhizomes mentioned earlier.
Over seeding is another option in August. Without destroying your existing lawn, mow it short, de-thatch, and aerate before applying the seed. Water as you would a new seeding. This method can improve your lawn by adding better seed varieties into areas with weak grass plants. The old plants will provide cover for the new plants.
Click on "Yard and Garden at the University of Minnesota Extension website for more on lawns and gardening information. Local Master Gardeners will respond to your questions via Voice Mail. Call 218-444-7916, leaving your name, number and question. Our Facebook page may also be of help to you: <https://www.facebook.com/Beltramicountymastergardeners/>.