Manage and prevent lawn weeds by promoting vigorous turf through proper fertilization, irrigation, mowing, and pest control. This results in thick, dense grass that shades soil and allows no space for weeds to grow. Reduce weed spread by mowing successive yards with clean equipment.
A weed is a plant that is not wanted or that is growing where it shouldn’t be growing. While weeds can be found in all locations from turf to pastures to roadsides, some are more commonly found in lawns and landscapes. These weeds are the ones we’ll look at in this blog.
Weeds can be classified by their life cycle and their type.
Annual weeds only last for one growing season, that is, they germinate, sprout, and die over the span of one season. Biennial weeds die after two growing seasons. Perennial weeds are those that grow for three or more years.
Weeds are typed by their growth habit. Broadleaf weeds have two seed leaves (cotyledons) present when the seed germinates, whereas grass weeds have only one seed leaf present. Sedge weeds have solid, triangular-shaped stems; rushes have solid, round stems.
Examples of broadleaf weeds include clovers, plantain, chickweed, Florida pusley, beggarweed, matchweed, and lespedeza. Examples of grass weeds include crabgrass, goosegrass, cogongrass, smutgrass, torpedograss, and annual bluegrass. Yellow and purple nutsedge, globe and annual sedge, and path and beak rush are common sedge and rush weeds.
How to Prevent and Manage Weeds
Maintaining a robust, vigorous turf is the best strategy for weed prevention and control. Dense, healthy turf shades the soil, and sunlight can’t reach weed seeds. Grass that is thick occupies soil space and there simply isn’t room in which weeds can grow.
A robust, vigorous, weed-free turf requires accurate cultural practices, monitoring areas of soil compaction, attentive pest control measures, and taking care to not spread weeds from one area to another.
Cultural practices include fertilization, irrigation, mowing, and pest control. Turf that doesn’t receive enough water, or turf that receives too much water, will be weakened. Turf that’s mowed too short or not mowed regularly may also be compromised.
Grass that is growing in areas where the soil has been compacted by foot or vehicle traffic will not be able to develop a healthy root system. This is especially true if the compacted soil is also wet. Saturated, compressed soil creates an environment that encourages weeds like goosegrass, annual bluegrass, dollarweed, and sedges.
Resolve the saturation issue and the compaction causes, and the turf will be able to grow strong roots and thick, healthy blades that resist weeds.
Turf pests attack grass and destroy it or cause it to lose vigor, which leads to susceptibility to weeds. The main reason this happens is that pest damage creates spaces between roots and blades, and opportunist weeds move in to those spaces. Controlling turf pests helps to minimize weeds.
Be intentional about keeping weed-free lawns weed-free. Don’t mow weed-free turf after mowing weedy turf without first cleaning off mower blades, trimmers, and edgers. Be careful of areas adjacent to lawns where there are weed populations. If weeds can be prevented from becoming established, the weed battle will be greatly minimized.
For more information, visit the UF IFAS Extension’s excellent article by Bryan Unruh, Ramon Leon, Barry Brecke, and Laurie Trenholm: Weed Management for Florida Lawns.