Dealing with Carpetgrass: A Guide to Effective Herbicides
Carpetgrass, a common lawn weed known scientifically as Axonopus affinis, can quickly take over your lawn, creating a dense, unsightly mat. It's a tenacious weed that can be challenging to eliminate, but with the right herbicide and a well-informed approach, you can regain control of your lawn.
What is Carpetgrass and Why is it Such a Problem?
Carpetgrass is a warm-season perennial weed that thrives in hot, humid climates. It spreads rapidly through stolons (above-ground stems) and rhizomes (underground stems), making it difficult to eradicate.
Here are the main reasons why carpetgrass is a problem:
- Rapid spread: Its ability to quickly create dense mats makes it a dominant weed in lawns.
- Competition for resources: Carpetgrass outcompetes desirable lawn grasses for water, nutrients, and sunlight.
- Unattractive appearance: The dense, low-growing carpetgrass can create an uneven, unappealing lawn surface.
Identifying Carpetgrass
Before applying any herbicide, it's crucial to correctly identify carpetgrass. Look for these characteristics:
- Blade shape: Carpetgrass blades are narrow and pointed, resembling the blades of some turfgrasses.
- Growth habit: It forms a dense, mat-like growth with stolons spreading across the surface.
- Leaf color: Carpetgrass typically has a darker green color compared to desirable lawn grasses.
Choosing the Right Herbicide for Carpetgrass
Choosing the right herbicide is key to effectively controlling carpetgrass. There are various options available, each with its own pros and cons.
1. Pre-Emergent Herbicides:
- How they work: These herbicides prevent carpetgrass seeds from germinating. They work by creating a barrier in the soil that interferes with seedling growth.
- Timing: Apply pre-emergent herbicides in early spring before carpetgrass seeds germinate.
- Examples: Products containing pendimethalin, dithiopyr, or prodiamine are common pre-emergent herbicides effective against carpetgrass.
2. Post-Emergent Herbicides:
- How they work: These herbicides kill existing carpetgrass plants. They are usually applied as a liquid spray and absorbed through the leaves of the weeds.
- Timing: Apply post-emergent herbicides when carpetgrass is actively growing, usually during the warm summer months.
- Examples: Products containing glyphosate, 2,4-D, dicamba, triclopyr, or fluazifop-p-butyl are effective against carpetgrass.
3. Combination Herbicides:
- How they work: These herbicides combine pre-emergent and post-emergent properties. They offer a longer-lasting solution for carpetgrass control.
- Timing: Apply combination herbicides in early spring to prevent germination and kill existing plants.
- Examples: Products containing a mix of pendimethalin and 2,4-D are commonly available.
Important Considerations when Using Herbicides
- Read and follow the label instructions carefully: Always follow the manufacturer's instructions for application rates, timing, and safety precautions.
- Target the weed, not your lawn: Be careful not to overspray and damage your desirable lawn grasses.
- Protect yourself: Wear protective gear, such as gloves, eye protection, and long clothing, when handling herbicides.
- Consider environmental impact: Choose herbicides that are environmentally friendly and minimize harm to beneficial insects, wildlife, and water sources.
Tips for Effective Carpetgrass Control
- Mow high: Mow your lawn at a higher setting to encourage healthy turfgrass growth and shade out carpetgrass.
- Water deeply and infrequently: Deep watering encourages deep root development in desirable grasses, making them more competitive with carpetgrass.
- Fertilize regularly: Proper fertilization provides nutrients for your lawn grasses, helping them outcompete carpetgrass.
- Overseed: Overseeding with desirable lawn grasses helps thicken your turf and displace carpetgrass.
- Hand-pulling: For small patches of carpetgrass, hand-pulling can be effective, but make sure to remove all the roots and stolons to prevent regrowth.
Conclusion
Controlling carpetgrass can be a challenging but rewarding process. By understanding the weed's characteristics, choosing the right herbicide, and following proper application techniques, you can effectively manage this stubborn weed and restore your lawn to its former glory. Remember, consistent effort and a well-informed approach are key to achieving long-term success.