Learn about the best organic controls for perennial weeds in the garden.
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While annual weeds such as chickweed, lamb’s quarters and pigweed have many control options, including eating them, perennial weeds really only have one; tenacity.
Japanese knotweed, quack grass, horsetail and gout weed are some perennial weeds that plague Vermont gardens. These weeds are specially adapted to survive. They’ve the ability to form new plants along their roots, so even if you pull out 99% of the plant, what’s left behind in the soil will eventually send up a new shoot. Herbicides may set them back, but really the only way to control these weeds is to be tougher than they are.
The first step is evaluation. If these perennial weeds have overrun your flower garden, it might be better to transplant the flowers and start over. If there are only a few weeds in the bed or they’re just starting to invade, frequent weeding, especially after a rain when the ground is soft and roots come up easily, is best. For new areas or places where they took over that you want to reclaim, draw a line in the sand or in the clay. Decide where they can grow and your garden starts. Cover the garden spot with black plastic, old rugs or some other heavy material. You can also mow every few weeks instead to weaken the plants. After a season, pull out the weaken plants, and as much root system as possible. Weed thoroughly every year to catch any strays. Dig a few foot deep trench and create a metal, wooden or plastic edge between your garden and the wild weed patch to prevent it from reinvading.