Managing Weeds
Part One
The most popular warm season turfgrasses grown in South Carolina are Bermuda, Centipede, Zoysia, and St. Augustine. Warm season refers to the fact that the grass prefers to actively grow during the warm temperatures of spring and summer and become dormant during the winter months.
Homeowners mainly want to rid their lawns of weeds because they are aesthetically unappealing. Weeds are also competitors of turfgrass and will rob the turf of sunlight, moisture, and nutrients. When left alone, weeds can grow out of control and can become a problem quickly. There are several different types of weeds. This week we will focus on broadleaf vs. grassy weeds and annual vs. perennial weeds. A broadleaf weed emerges from seed with two leaves that have netlike veins and many have showy flowers. For example, dandelion or white clover have very showy flowers. Grassy weeds emerge from a seed as a single leaf. The leaf blades are longer than they are wide and have parallel veins. Examples of grassy weeds are annual bluegrass, dallisgrass, and crabgrass. Annual weeds germinate, grow, and die within a 12-month period. Summer annual weeds such as goosegrass or crabgrass, germinate in the spring, grow through the summer, set seed, and die at the onset of cold weather. Winter annuals, such as chickweed, henbit, purple deadnettle, or annual bluegrass, germinate in the fall, grow throughout the winter, set seed and die as temperatures rise in early summer. Perennial weeds grow for two or more years. They reproduce from vegetative parts such as tubers, bulbs, rhizomes, or stolons, although some produce by seed. Examples of perennial weeds include dallisgrass, nutsedge, white clover, and plantains. Perennials tend to be more difficult to control.
Weed control begins with proper management practices. A thick turf minimizes the space available for weeds to become established and shades the soil so less sunlight reaches the ready to germinate weed seeds. Best management practices include proper:
• Mowing height & frequency
• Watering rate & frequency
• Fertilizer analysis, rate & timing
• Liming as recommended by a soil test
• Core aeration to reduce soil compaction
• And de-thatching as needed.
Stay tuned for upcoming news articles for more information on best management practices on turfgrass and controlling weeds using herbicides.
For more information on types weeds in warm season lawns, please visit the HGIC website at hgic.clemson.edu. Tune in on Tuesday nights to watch “Making it Grow” at 7pm on SCETV or mig.org. Email Callen Outen at callenb@clemson.edu or call at 843-627-7113. *Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political beliefs, sexual orientation, gender identity, marital or family status and is an equal opportunity employer.