I recently had a call from a gentleman who had cleared some property around a house and was looking for a good ground cover to hold the soil and look nice as he prepared to sell it. While I’ve written fairly frequently about the benefits of cool-season annual grass species such as annual ryegrass for their benefits to grazing livestock, I haven’t spoken much about warm-season annuals. The most common warm-season annual grass is one that most folks consider an undesirable weed- crabgrass. There are a variety of crabgrass species, but all of them are summer annuals, meaning they actively grow during the hot months of the summer and each plant only persists for a single growing season. Crabgrass is a fast-growing, clump-forming brass that grows low to the ground with stems radiating outwards. Whether it’s your preference or not to have this species on your property, I thought I’d share a bit of information about it this week.
Crabgrass is often considered a weed, which just means it’s unwanted and competing with a desired species – in this area, often a bermudagrass. Since it is an annual species, it needs to repopulate from seed each year, which can inform how we manage it if it’s acting as a weed. Pre-emergence herbicides, which prevent seedlings from developing into mature plants, can provide excellent control of crabgrass, but they must be applied at the correct rate and time to be effective. Be sure to match your herbicide selection to your desired turfgrass species and follow all label instructions for use. At this time of year, we’re too late in the season for pre-emergent herbicides to be very effective on the initial growth of crabgrass; but an application may still reduce some of the crabgrass burden if used now. If you’ve missed the pre-emergent window, a post-emergent herbicide can be used to help control the emerged crabgrass seedlings. Consistent mowing that prevents the crabgrass plants from producing seed can also be effective at reducing populations in the following season, but this is often very difficult to do well.
While many consider crabgrass a weed, there are some scenarios in which it can be beneficial. As in the case mentioned above, my client needed a quick-growing groundcover to hold soil through the summer – crabgrass can do this easily. While it’s not the first ground cover people turn to, it can be a viable option. We also have prior research that crabgrass produces a very palatable and nutritious forage for grazing livestock. One of our local producers has even produced crabgrass hay in the past, which upon testing, outperformed other forage species. Generally speaking, crabgrass provides the highest quality forage than other summer annual species, producing from May till October or so. If you’re a livestock producer or have grazing animals, a little bit of crabgrass in your pastures is not necessarily the end of the world; though you do want to be cautious that it doesn’t overrun and kill off your desired perennial species.
If you need more information on crabgrass or other forage species, please let me know at uge3181@uga.edu or 706-359-3233.
