Can I get rid of quack grass by turning over the soil and letting the sun dry out the roots?
Quack grass is notoriously difficult to control because it primarily spreads by sending out underground stems known as rhizomes. If even a small fragment of one of these rhizomes remains in contact with the ground after the plant has been dug up then roots will grow and a new plant will form.
For that reason, simply turning over the soil won't be terribly effective.
If you were to go a step further and leave the grass plants and their roots to dry somewhere where they wouldn't come in contact with the soil, you might stand a chance. However, if you leave them to dry in or on the soil, the rhizomes will re-root and pretty soon you'll be back to where you started.
There are other things that you can do that will stand a better chance of being effective.
Solarization is sometimes used to control quack grass. This method involves laying clear plastic on the ground during the hottest days of the summer and firmly securing the edges to minimize heat loss. The temperatures underneath the plastic will reach levels sufficient to kill any weed seeds or rhizomes left in the soil. The plastic will need to remain in place for a minimum of six weeks for this method to be effective.
You can also mulch the affected area with black plastic (aka plastic mulch) and leave it in place for at least six months.
If you use either solarization or plastic mulch, you should plant a cover crop as soon as you've destroyed the quack grass to recover the minerals that have been released into the soil and to prevent the quack grass from muscling its way back in. Once you turn the cover crop under, you can plant as usual.
Another control that can sometimes be effective involves using a hoe to remove the above-ground parts of the plant on a regular basis. Since plants require photosynthesis to create the energy they need to survive, if you repeatedly impede the plant's ability to photosynthesize then even an aggressive plant like quack grass will eventually die.
Many non-organic gardeners resort to non-selective herbicides to make the job easier and although these chemicals are effective in killing the quack grass, they won't prevent it from returning, which means, of course, regardless of the method you choose to control the quack grass, it'll eventually come back.
If you have any questions or comments, please send them to me at vanessa@gardenmuse.ca.
