A troublesome summer annual weed that can invade home lawns is goosegrass, which some refer to as “silver crabgrass.” Although goosegrass may closely resemble crabgrass, there are some key distinguishing features that will help you to properly identify and treat the weed, which can often be difficult to control. Goosegrass is widely spread throughout the United States and is most often a problem during the warm summer months, but will persist into the winter months in the southern parts of the country.
Pictured above: Goosegrass with obvious silver/white stems.
To identify goosegrass, many say that it appears flat—like someone has stepped into the middle of the plant. The leaves of goosegrass are a dark green color and the stems become a silver/white color as you move towards the center of the rosette. The flowers on the plant first begin to appear towards the middle of the summer and produce spikes that resemble a zipper. It is able to grow where other plants struggle and can often be found in compact soils that have poor drainage, which are common in thin areas of lawns that experience heavy traffic. A single goosegrass plant can produce up to 50,000 seeds which will typically begin to germinate when soil temperatures reach 60 to 65 degrees. This is approximately two or more weeks later than crabgrass. Unfortunately, goosegrass can spread from one lawn to the next as seeds are picked up by wind, so bare spots in the lawn can quickly become a harbor for unwanted plants to germinate.
Pictured above: Goosegrass in moist soil next to a drainage pipe.
Goosegrass Non-Chemical Control
Something important to note about goosegrass is that it is rarely found in healthy, dense lawns; therefore, there are many cultural practices you can implement to help keep your yard free of this pesky weed. As always, proper fertilization, mowing and irrigation are essential to maintain a healthy lawn. Since goosegrass does well in compact, poorly drained soils, reducing irrigation so that you do not overwater, along with incorporating aeration to relieve compaction can be a big help. If this is not a possibility, changing the traffic patterns can help to relieve compaction and improve drainage. Goosegrass also has a centralized root and can be removed by hand; however, once the weed gets larger than a few inches, a gardening tool may be necessary to remove the plant and its entire rooting system. Read our Soil Management for Lawns and Gardens blog for more information regarding different soil types and soil health.
Goosegrass Chemical Control
When looking to chemical controls, there are several pre-emergent and post-emergent options, with pre-emergents being applied initially in February or March, and a follow-up application occurring six to eight weeks later if needed. A pre-emergent herbicide serves to prevent goosegrass from appearing whereas a post-emergent controls the weed after it has appeared. One common pre-emergent is Prodiamine 65 WDG, which is tank mixed with water and can control goosegrass in one application. Another pre-emergent that will control goosegrass is Dimension 2EW (active ingredient Dithiopyr), which should also be tank mixed with water. If goosegrass has already become established, a post-emergent option is Mesotrione, which can be used as a spot treatment or for full coverage; however, it may cause turfgrass leaves to whiten slightly for a few weeks as it kills the weeds. An additional post-emergent option is Revolver (active ingredient Foramsulfuron), which is applied as a broadcast spray that is quickly absorbed and can stop the growth and cell division of weeds within a few hours.
It is very important to read the product label carefully before making a chemical application to ensure that it will be compatible with your turf and not cause any damage. To learn more about identifying what kind of weeds you may have in your lawn so that you know how to best remove them, check out our Identifying Common Lawn Weeds blog. For more information on weed control in general and the best ways to reduce weeds, visit our Weed Control blog.