Weeds and lawns are almost inextricable companions. If you live in the South where warm temperatures speed weed growth, you're likely to encounter diverse weeds that may easily overwhelm your lawn. Fortunately, a few key characteristics are the most important things you need to know to identify your lawn weeds. If you want to go further in learning about these unwanted plants, there are a number of resources available to show the way.
Lawn weeds in the South or anywhere else are either broadleaf or grassy. Obviously, the most easily identifiable characteristic to distinguish between the two is the leaf; wider leaves are broadleaf weeds, narrower leaves are grassy.
Another important, but more difficult, distinction is if weeds are annuals, biennials or perennials. When you want to rid your lawn of these pests, you're unlikely to want to observe their life cycles.
Learning to recognize specific weeds through photo identification is one way to put a name to your weed and learn more about it. The University of Georgia Turf program is one site that provides mug shots of broadleaf and grassy weeds with accompanying information.
Keying Your Weeds
Keys for determining you weeds are widely available; if you want or need to know the precise identity of your lawn weeds, resources that provide detailed information on leaf, stem and root characteristics, rather than flowers, are most useful to homeowners. You want to identify your weeds before they have a chance to flower and go to seed. One example of such a resource is the North Carolina State University TurfFiles key.
Local Lawn Weed Identification
Some weeds, such as dandelions, are present almost everywhere, but others may dwell in your corner of the world, but aren't familiar elsewhere. Identifying weed lists for your area may help when what you're seeing is not a dandelion or crabgrass. Southern states all have Cooperative Extension materials online and most county Extension offices offer free weed identification through plant clinics and Master Gardener information services.
Effects of Lawn Type
Much of the South is in a transition zone for lawns; both cool season and warm season grasses are recommended for a great portion of the region, and the differences in growth habit and maintenance practices for the two will affect the types of weeds you're likely to see, as well as how to treat them.
Cool-season grasses, such as fescues and Kentucky blue grass, are clump forming and should be kept taller than the warm-season, spreading grasses, such as Bermuda, St. Augustine and zoysia.
Weeds that thrive in cool weather, such as chickweed, clover and henbit are fierce competitors of warm-season grasses, such as St. Augustine grass, warns Texas Cooperative Extension turfgrass specialist Richard L. Duble. On the other hand, warm-season weeds, particularly perennials such as nimblewell and wiregrass, can take over large portions of cool-season lawns, according to the Virginia Cooperative Extension's Mike Goatley.
Identifying your Southern lawn weeds is the second step in having a weed-free lawn. The first step is prevention through proper lawn establishment and maintenance. Identifying the weeds that do appear is one way to tell where your turf practices are falling short. For example, weeds may indicate your soil acidity, fertility or moisture levels are not optimum, that you're mowing too low or that the area is too shady for a lawn.
Once you have identified your weeds, correcting cultural conditions is as important as removing weeds or using herbicides to control them. Consider replacing lawns with other ground covers, ornamental plantings or mulched areas, if you can't meet the requirements for healthy turf.