The Vine That Binds Us

By Carmine Carosella, Fairfax Master Gardener
Ah, the beautiful morning glory! They provide flowers in many colors for pollinators and instant summer shade as they weave up structures, even a favorite of hummingbirds. I remember the sky-blue flowers growing up telephone wires in Boston, easily twenty feet long. But wait, do you want them wrapping themselves around your garden fences, hiding in your tomato plants, climbing your bean poles? Morning glories become a nasty weed in the vegetable garden and can rapidly take over your plants. What’s a gardener to do? Well here are some thoughts.

First, Virginia Tech’s weed website lists 10 different wild morning glories in our region. I have two in my garden and yard, Ipomoea hederacea which has ivy-shaped leaves and Ipomoea hederacea var. integriuscula which has heart-shaped leaves. Both have purplish flowers and are annuals, though you’d never know it because they seed so prolifically and the seeds last up to 20 years in the ground. The vines can grow up to 10 feet, and the seed pods contain 3-4 seeds. They both belong to the family Convolvulaceae that also contains the truly nasty bindweed, Convolvulus arvensis, which grows similarly to morning glories but is a perennial and an invasive from Europe. It usually has white flowers and is virtually impossible to control without glyphosate.

You must prevent the morning glory from flowering. They are most prevalent along fence lines. Take your weed trimmer and run it along the base of the fence which will easily cut all the morning glory vines. If you let them go to flower, then you’re faced with the task of picking off the seed heads from the vines, a very tedious job.

Pre-emergent chemicals are completely ineffective in stopping the morning glory seeds from germinating as they keep sprouting throughout the season. Vigilance with hand-pulling or hoeing is a must. And the plants camouflage themselves so well with pole beans. Usually the first sign of attack is a blooming flower instead of a bean. Pick off the flowers and cut the vine near the ground. Removing the vine itself is usually impossible.

You’re faced with a multi-year task once the morning glory seeds are in the ground. Thick mulches along fence lines will prevent seedlings from sprouting in the spring. But constant vigilance is the only true solution. Good luck!

References
Ivyleaf and Entireleaf Morning Glories, Michael Flesser, Virginia Tech Weed Identification Guide
Morning Glory Control, Bonnie L. Grant, Gardening Know How
Ivy-Leaved Morning Glory, Illinois Wildflowers