Identifying Oklahoma Lawn Weeds

Oklahoma has a climate with cold winters and hot summers. The state is generally dry and sunny most of the year, with precipitation on average of 15 inches in the Panhandle to over 50 inches in the southeast portion of the state. According to American Lawns, warm season grasses like ermudagrass, buffalograss and zoysia grass are common choices for Oklahoma lawns, though cold-season Kentucky bluegrass and tall fescue can also be found. Weed control measures can be facilitated by accurate identification of the problem plants.

Examine the plant shape and color. Crabgrass grows flat and close to the ground with legs growing out like a crab and is usually lighter in color than the surrounding lawn. Splurge starts out with a small rosette of leaves that eventually forms into a dense mat. Dallisgrass grows tall and leggy with a light-green color and long seed heads. Nutsedge is yellow-green with leaves growing from the base of the plant in groups of three. Dandelion has dark-green, ragged leaf edges and produces delicate puffballs that spread the seeds on the wind.

Measure height and density. Chickweed grows low to the ground in mats with branching stems that root at nodes. Small clusters of flowers grow at the ends of stems. Goosegrass, or wiregrass, appears as a whitish, silvery mass with stout flower stalks. Henbit can grow up to 12 inches, spreading purplish flowers throughout the lawn. Foxtail is an upright plant that can grow to two feet if not deterred, with a fuzzy seed head that is dense with seeds

Check growth characteristics. Crabgrass germinates from April to July and its seeds continue on to October. Crabgrass will root at the nodes and produce seed heads of two to six fingerlike branches. The smooth variety has hairless leaves, while the large crabgrass variety has hair both on the blade and the sheath. Foxtails will germinate from April to June, with seeding until September. The leaves form into dense heads, with two florets per spike. Goosegrass will germinate in May to June, with seeds spreading until October. It produces fingerlike braches with two to nine fertile florets and then a hulled, dark-brown seed, according to the Oklahoma State University.

Consult with university agricultural extension service. If you are unsure about the type of weed you are trying to eliminate, your local university agricultural extension service can not only help you to determine what type of weed it is but can advise you on the best methods of control. Today, local agencies are very concerned about the amounts and types of herbicides being used and how they affect fish and plants in local waterways. They will help you to find the most effective method to eliminate the weeds with the least amount of toxins being added to the environment.

Dallisgrass is often confused with crabgrass.