Bridge Gardens’ Weed of the Month | Field bindweed (Convolvulus arvensis)

This relative of morning glory is one of the most difficult weeds to eradicate and control. Responsible for crop losses exceeding 400 million dollars every year, it is a serious pest in agricultural fields, as well as a nuisance for home gardeners, smothering and significantly damaging ornamentals in a single season.

Native to Europe and introduced into North America in the eighteenth century, field bindweed is a perennial vine with arrow-shaped leaves and white or pink trumpet-shaped flowers. It grows 4-6 feet long, creeping along the ground until it finds a plant or structure to climb, and can spread by seed and by an extensive underground root system. Seeds are not produced in abundance, but persist in the ground for years. Roots grow as deep as 9 feet, but most are found within the top 2 feet of soil.

Difficult to eliminate, even with herbicides, bindweed can best be controlled by hand pulling or digging up plants. Persistence and commitment to the cause are key, as it can take 3-5 years or more to achieve results. Plants quickly regrow after pulling and small fragments of roots easily become new plants. So, plan to weed or cultivate this invasive every 3 weeks throughout the growing season.

Another method of control is to cover areas infested with bindweed with a thick barrier to block the sun and shade it out. Bark or straw mulches are not recommended as they decompose before control is achieved. The same is true for cardboard. Weed-suppressing fabrics or tarps are more effective, but need to be left in place for 3 or more years. They need to be free of holes and have their seams well-overlapped, as bindweed is able to seek out any bit of light and start growing again.

At Bridge Gardens, we have 3 areas infested with bindweed. The Community Gardens compost pile was completely covered by bindweed last season, so this fall, we had it bulldozed and consolidated into a small hill and covered it with a large tarp. Our hope is that in 3 years or so, the bindweed will be smothered and cooked, along with all those tomato, squash and cucumber pathogens.

The beds above the rose garden are also infested. There, we’re hoping all the trees and shrubs we’ve planted will eventually shade out the bindweed. In the meantime, we’ll pull the bindweed on a tri-weekly basis and plant cover crops that may outcompete it. The third area is under the pine trees at the end of the Tales on the Trail story walk. This area will also be covered and then mulched to disguise the tarp.

We’ll keep you posted if there are any signs of success. Stay tuned and good luck to us all!