COUNTY AG NEWS

Spring Lawn Care

Concerns

The severity of winter damage will influence what should be done to bring the lawn back in shape. If the area is completely killed it may be necessary to completely work up the lawn and reseed the entire lawn. If the lawn is just a little thin, overseeding with a quality lawn seed may be the answer. Seed may also be broadcast over thin lawn areas, but there needs to be good soil to seed contact. Dethatchers or vertical mowers can also be used to tear out excess debris prior to overseeding. All of these types of overseeding procedures do not require additional soil modification.

For those homeowners who work to have the dark green, weed free lawn one of their major concerns is the presence of crabgrass later in the summer. Crabgrass is a warm-season annual grass. This means that any new weeds this year must grow from seeds in the soil. Crabgrass will not start germinating until soil temperatures get around 55 to 60 degrees.

The use of a preventative pre-emergence herbicide is the key to controlling crabgrass. These need to be applied to the lawn before crabgrass germinates. Most pre-emergence crabgrass herbicides are found in combination with lawn fertilizers, so crabgrass prevention and spring fertilization can be done at the same time. Follow the rates given on the bag.

One word of caution, pre-emergence herbicides for crabgrass will also damage germinating desirable grass seed. Usually one application applied at the proper time, around mid to late April, gives adequate season-long control. If an application is made very early in the season, a second application may be necessary during the later part of June in order to prevent crabgrass infestation later in the summer.

Crabgrass prefers full sun, moisture, and thin lawns that allow light to hit the soil. Sound lawn care practices to allow for thick, vigorous lawns that shade the soil help prevent crabgrass from becoming a problem. Mowing height perhaps has the most impact on crabgrass. Mow between 3 and 3½ inches and there will be fewer crabgrass plants in your lawn. In addition, avoid frequent watering, especially frequent light sprinklings. If possible, hold off lawn establishment or renovation work until late summer to avoid potential crabgrass problems from appearing on open soil areas in lawns.

A lawn fertilization program should begin in early October, not early May. Spring applications can actually harm lawns by promoting more leaf growth rather than root growth. Shallow root systems are unable to sustain lawns through a drought or a harsh winter.

Fall applications promote deep healthy root systems and hardy lawns. Broadleaf weeds, such as dandelions, spurge, or creeping charlie may require the use of a broadleaf herbicide or plant killer. While applications in the spring will usually achieve acceptable results, fall applications around Oct. 1 will usually result in a better level of control since perennial weeds in the fall are translocating nutrients into the root systems and as a result more of the herbicide will be moved into the roots.