How do you get rid of witch grass? I have tried almost everything and it keeps coming back!
The Gardener’s Answer
Hello, Catherine: Witch grass (Panicum capillare) is known by several common names, including panic grass and tumbleweed grass. This weedy, warm-season grass is a North American native that can be difficult to get rid of once it has found a home in your garden. It is an annual grass that can reach 1-3 feet tall. Since it is an annual we do not have to worry about the same plant returning year after year, but we do need to be concerned about the seeds it produces. If this grass is allowed to flower it can produce tens of thousands of seeds per plant. Since it is such a prolific seed producer, not allowing it to flower will drastically reduce the number that will show up in years to come. The seeds can remain in the soil for up to three years before they germinate. Do not be too discouraged, you have already started the elimination process from the effort you have already put into this project. It is that the seed can lay dormant for so long that eradicating them all in one year is not possible. As warmer weather arrives and the seeds germinate, the process will continue so tackling it early will leave less work for the upcoming years. The key is to not let the grass flower. I am not sure what you are dealing with in terms of space or what you have tried in the past, but here are a couple of options. First, hand digging is always the safest and most environmentally friendly. If this is not feasible, corn gluten is a great pre-emergent that will stop the seeds from germinating if applied early enough. This would not be an option if this is a space where other intentional seeds are germinating. Spot spraying with any weed killer containing glyphosate, such as Roundup, will work but always use caution when using chemicals. Getting to the grass while it is young will be less maintenance on your part if you can pull them, otherwise just make sure you get to them before they flower and produce more seeds.