MAINTAINING A HEALTHY LAWN

Spring
Rake lawn gently when frost is out and ground is dried sufficiently. Raking when the ground is too wet may cause damage to crowns of grass. Normally de-thatching is not necessary. Check for thatch layer and if it is more than one inch thick then dethatch. If lawn seems hard and compacted with poor doing grass consider core aeration.

Fertilizer
Fertilize the first time in the spring near Memorial day. This allows grass to become established and well rooted. Fertilize again in late summer around Labor day. Frequent fertilization weakens grass plants and requires more frequent mowing.

Mowing
Set mower blade at 21/2 to 3 inches. Mow it tall-let it fall should be your motto. Make sure the lawn mower blade is sharp so you are cutting rather than tearing the grass. Never remove more than a third of the plant with each mowing. Mowing close to the ground weakens plants and exposes the to sunlight soil so weeds can germinate. Setting the mower higher allows the grass to shade the ground so fewer weeds germinate, allows the grass to compete better with weeds and requires less water during periods of heat and stress. Allow grass clippings to return to the lawn. They are mostly water(75%) and will dry up and decompose rapidly. Contributes mulch and saves time and energy. Lawns will also require less fertilizer as we recycle the nutrients in this manner. Never mow in the same direction, alternate mowing patterns as this allows the grass to thicken and not develop a grain or seam pattern. Mow in the evening or cooler part of the day to allow grass to recover overnight. Make the last mowing of the year 1 inch shorter to avoid snow mold and mice problems over winter.

Weed control
First line of defense is a healthy lawn. Mother nature hates a void so weeds will invade any open areas. 

Broadleaf weeds- Dandelions consider a spring and fall application of a 2,4-D herbicide. Herbicides such as Trimec and Confront are good on clovers, chickweed, creeping charlie etc. 

Grassy weeds are more difficult as there are few herbicide choices for grassy weeds in lawns. If crabgrass is a problem use a pre-emergent such as Dacthal in early May. Crab grass is an annual that germinates each year. 

Quack grass- we either decide to live with it or kill out the lawn with Round-Up and start over. Again a healthy lawn is the best defense.

Watering
Kentucky bluegrass is a cool season grass. It naturally goes dormant during hot dry weather or periods of stress. If watering continue to water during hot weather. If you allow to go dormant don't allow grass to dry out completely. Water enough to keep crowns alive. Avoid frequent light watering. It does nothing but encourage shallow root system and weakens plants. When watering provide a good soaking once or twice a week depending on weather, providing at least 3/4 inch of water at a time.

Dale L. Siebert
Extension Agent/Cropping Systems
Richland County Extension
418 2nd Avenue N.
Wahpeton, ND 58075
701-642-7793
dsiebert@ndsuext.nodak.edu

Horticulture Home Page.
Richland County Extension Home Page.