Summer is a successful time to kill weeds, either by mechanical weeding or with herbicides. But toxic herbicides, like Roundup are not solutions we recommend. Roundup in particular was once believed to be quite safe, but now is shown to be harmful to soil life including nitrogen-fixing bacteria, amphibians and is a probable human carcinogen. Roundup formulations can be up to 400 times more toxic than the active ingredient, glyphosate.
At Harlequin’s Gardens, we only sell non-toxic products, but not all non-toxic products are actually effective. Four years ago we tested five non-toxic herbicides and found only two to be really effective: 20% Vinegar and Avenger.
20% Vinegar is 20% acetic acid. It is a non-selective organic acid that quickly kills many weeds, then quickly biodegrades. Repeated use can acidify the soil which is usually a benefit in our alkaline soil. Be careful not to spray desirable plants, and be careful to protect your eyes, especially on windy days. It is most effective on small plants. Repeated applications may be necessary on perennial weeds.
Avenger is a citrus oil weed killer that we found to be equally effective as the vinegar. It is certified organic and is biodegradable. Avenger is non-selective so care must be taken to keep spray off desirable plants. It comes in a ready-to-use (RTU) formula and in a concentrate which may be mixed stronger for tougher, perennial weeds. Like vinegar, it is most effective on small plants, and is best sprayed during hot weather in direct sunlight.
In order to “control” bindweed and other weeds with extensive root systems, don’t let new growth get longer than 2″ or the weed will revive.
BLISTER BEETLE: We have been hearing reports of Blister Beetle attacking clematis. This is a light grey, long beetle that can defoliate a clematis vine in 2 or 3 days. We have found that an organic product called Veggie Pharm actually kills this beetle. It must be sprayed directly on the beetle. (Don’t try to pick up a Blister Beetle; they can raise a blister)
Tree Wrap: We recently saw a big buck with his antlers in the velvet stage. This the time of year deer cause the most damage, when bucks rub their itchy antlers on smooth, usually young tree trunk, tearing the bark. Sometimes a young tree can be girdled in one night. We carry a very good spiral plastic tree wrap that protects trees from deer, rabbits, sun scald in winter. It is superior to paper wraps because it lets air circulate so moisture does not decay the bark. It can be left on in the summer and it expands as the tree grows. Once the bark is older and tougher, it will no longer need protection.