An article by Mary Trainer, MGiT with OMG
Getting rid of weeds that grow up through landscaping cloth, among rock gardens or in gravel areas at curbsides can be challenging.
In my yard – and many others in the Okanagan, cheat grass (downy brome) and quackgrass (Elymus repens) are the main culprits.
What to do? If I’m having trouble, I thought, chances are many other gardeners are too.
As a Master Gardener-in-Training, I sought advice from Kathryn McCourt, who knows a thing or two about weeds. A master gardener for 40 years, Kathryn was a founding member of the Penticton Farmers’ Market and Penticton Urban Agriculture Association. Currently, she is a volunteer at the Summerland Ornamental Gardens, with a focus on helping plants survive our increasingly erratic weather.
Advice on weed control from Kathryn McCourt
Kathryn’s first choice involves vinegar, but not what you might have in your kitchen.
“Household vinegar is only 5% acetic acid, so I use cleaning vinegar that’s 10% acetic acid, available at hardware stores,” says Kathryn.
To four litres of vinegar, add 15 ml of dish soap detergent. Mix it up and spray it full strength directly on the weeds so that it contacts the stems and leaves. The detergent helps the vinegar adhere to the surfaces. The vinegar works to remove moisture, and the weeds eventually die.
You may see results with a day or two. Quackgrass is a perennial and continues to come back, so expect to apply the spray again.
If you’re not getting results, give the solution an extra kick by adding a cup of salt, which helps to dry out the weeds.
Tips for using vinegar on weeds
Wear gloves, long pants and sleeves to protect your skin.
Choose a time of day to spray when it’s not hot, otherwise the vinegar may evaporate. Spray on a rain-free day or when rain isn’t forecast to avoid the spray washing away.
Be careful where you spray, because although the solution will kill weeds, if it contacts nearby plants, they could die too.
Use sparingly, as excessive use can negatively alter the pH in your soil.
Kathryn says this solution is effective. But remember: weed seeds can still regrow. Also note that it won’t kill dandelions because the vinegar only affects the surfaces of plants and not their roots.