Wild Onion & Garlic | Sunnyside MG

Wicked Weeds: Wild Garlic and Wild Onion

By Jane Jones

I know it’s time to begin my spring garden work when the wild garlic (Allium canadense) pops up overnight in my plant beds and lawn. Wild garlic and its close cousin wild onion (Alliium vineale) are winter perennials which emerge in early spring, go to seed and die back in the summer, only to emerge again for another round in late fall. Both grow from underground bulblets that can remain in the soil for several years and will faithfully continue to form new bulblets.

Wild onion and wild garlic are related to the green onions or scallions we use for cooking, but the leaves are thinner. They grow in clumps, are taller than the surrounding grass, and emit an onion/garlic aroma when pulled or the leaves are cut. The two are easily confused. They can be identified most easily by an inspection of their leaves. Wild garlic has hollow leaves and wild onion has solid flat leaves. They propagate by seed or by growing new bulblets.

Control of both is challenging. They cannot be pulled successfully –a fact I’ve learned the hard way. One option is to dig small clumps that are in planting beds, but every piece of bulblet or root must be removed. Throw the clump away—do not put in the compost pile because the bulblets will survive the composting process and grow wherever the compost is used in the garden. Mowing will not eradicate bulblets in the grass, but it will weaken the plants and prevent them from going to seed.

For chemical control, a broadleaf weed killer that contains 2,-4D and dicamba can be used for spot treatment. Glyphosate can be used on larger areas but use carefully since it will damage surrounding vegetation. Since herbicides do not adhere easily to the waxy leaves, bruise the leaves before applying any chemical. Follow manufacturer’s instructions on the label carefully and be prepared to administer the chemical for 2 or 3 years before the plants are eradicated . March, April, May, and June are optimal months for treatment.

References:

Clemson Cooperative Extension. https://www.clemson.edu/extension/hgic/pests/weeds/hgic2311.html

Missouri Botanical Garden. http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/weeds/wild-garlic.aspx