Click for larger image Clump of wild garlic (Allium vineale); also called, field garlic, scallions, crow garlic; can be a pest of lawn or garden

Wild garlic, Allium vineale, and wild onion, A. canadense are common weeds in lawns. The easiest way to tell them apart is by their leaves. Wild garlic has hollow leaves and wild onion has solid flat leaves. Both are noticeable in lawns where they generally grow faster than the surrounding grass. Control is the same for both species.

Integrated Pest Management Strategies

1.Dig plants. For isolated plants, dig and remove all of the underground bulbs or replace the whole shovelful of soil with clean soil. Replant or resod the spots. Pulling the plants is not effective because many bulbs or bulblets are left underground where they continue to grow and multiply.

2. Use chemical herbicides. Spot treat plants with a broadleaf weed killer that contains 2,4-D and dicamba. This includes most common broadleaf herbicides that are readily available. Check the label for control of wild garlic and onion. Before applying the herbicide, bruise the leaves by stepping on them to allow better entry of the chemical into the plant. Begin applying in early spring and reapply as new plants develop. Treatment is best done in March, April, May, and June. Complete control may require 3 years of treating. Be very careful when using weed killers near other plants or over the roots of trees and shrubs in the lawn as they can damage these plants.

Scattered plants can also be killed with glyphosate (Roundup, Kleenup). Bruise leaves and mop or swab the herbicide mixture on the leaves taking care not to get it on desirable plants.  Glyphosate (Roundup, Kleenup) is nonselective and will damage or kill most plants it contacts, including lawn grasses.

Heavily infested areas can also be killed with glyphosate (Roundup, Kleenup) and the area replanted in the fall. Since dormant bulbs may not be killed by glyphosate (Roundup, Kleenup), there will most likely be a reoccurrence at a later date that will need to be controlled with a broadleaf weed killer.

3. Ignore the problem and it will "disappear" for most of the year. Both species grow actively in late winter and early spring and go dormant with the onset of summer. Meanwhile, practice sound management techniques appropriate to your turf type to thicken the lawn and reduce the niche that allows these weeds to thrive.

Organic Strategies

Strategies 1 and 3 are strictly organic approaches.

More images:

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Flower of Star-of-Bethlehem (Ornithogalum) is a bulbous perennial that might be confused with wild garlic or wild onion and is controlled in the same way. ID tip: leaves have no scent when crushed
Click for larger image
Star-of-Bethlehem (Ornithogalum) is a bulbous perennial that might be confused with wild garlic or wild onion and is controlled in the same way. ID tip: leaves have no scent when crushed