It is considered a secondary or B-rated noxious weed in California, Minnesota, Texas, and many other states. It thrives in moist, disturbed soil.
Typical of a weed, it can survive in multiple soils including saline and alkaline conditions and peat or even gravel.
It is highly competitive in agricultural settings and able to reduce crop yields. Data from Michigan State University point to potential loss of potatoes of 85% and corn at 37% on high level infestations.
In turf, it can be less noticeable while it is reproducing and slowly taking over areas. Quackgrass has also shown to be allelopathic. This means that the plant will release substances toxic to other plants inhibiting their growth and development, allowing the quackgrass to establish a stand of its own.
This is another non-native weed species originating in North Africa and Eurasia.
Weeds are broken down into two basic classes – grassy or grass like, and broadleaf weeds. Not only are the grassy weeds tougher to identify, but they can be equally as complicated to manage.
This really holds true in cool season turf. If they exhibit an annual life cycle, at least you have a chance provided you can time and apply preemergents properly. Perennial grassy weeds in cool season turf often pose a much more difficult task as there are very few if any selective controls in this situation. That statement could not be pertinent for Quackgrass.
Identification can be tough, as younger plants are often mistaken for crabgrass, tall fescue, orchardgrass, and some ryegrasses as well as others. Only by closer examination can you determine the differences.
The foliage is a bluish green with somewhat coarser and longer leaves which tend to have a wavier margin and sometimes a longitudinal twist. Veins are prominent on the upper leaf surface and ligules are very short and may be fringed.
The big identifier is the clasping auricles, or ear-like extensions of the leaf into the collar region. They will be long and claspy around the sheath, particularly in more well-established plants. Younger plants may have less well-developed auricles, but they will still be present.
The other structures to look for are the rhizomes. The underground structures are rigid, sharp-tipped, and extensive. These subsurface stems are what make hand weeding and cultivating ineffective as they will sprout new shoots once broken from the mother plant, and they aid in thick patch formations.
In fact, the species name repens refers to its creeping or spreading habit. These rhizomes are particularly noticeable when attempting to pull the weed - they keep trailing like string through the soil.
Quackgrass is also able to withstand mowing pressure, so height of cut is not a control strategy.
Now here is the downside: there are very few options for control. Pulling and tilling can make it worse and should be avoided. There are no biologicals and even selectives like Tenacity are unsuccessful. According to research performed by Nick Christians at Iowa State University, Tenacity will turn it white on first application, but it will come roaring back. Even with subsequent applications and four years of trying, he was not successful.
As it stands, spot or dab treatments with non-selectives, primarily glyphosate, are your best option. In the lawn, maintaining thick, healthy turf will help.
Contact the Ewing Technical Services Team with any questions.