- What is it? Garlic mustard is a cool-season
biennial herb that ranges from 12 to 48 inches in height as
an adult flowering plant. Leaves and stems emit the
distinctive odor of onion or garlic when crushed
(particularly in spring and early summer), and help
distinguish the plant from all other woodland mustard
First year plants consist of a cluster of 3 or 4 round,
scallop edged leaves rising 2 to 4 inches in a rosette.
Second-year plants generally produce one or two flowering
stems with numerous white flowers that have four separate
- What's the problem? Garlic Mustard is a rapidly
spreading woodland weed that is displacing native woodland
wildflowers in Wisconsin. It dominates the forest floor and
can displace most native herbaceous species within ten
years. This plant is a major threat to the survival of
Wisconsin's woodland herbaceous flora and the wildlife that
depend on it. There are two modes of spread: an advancing
front, and satellite population expansion possibly
facilitated by small animals. Unlike other plants that
invade disturbed habitats, garlic mustard readily spreads
into high quality forests.
- How is it spread? The seeds are believed to be
dispersed on the fur of large animals such as deer, horses,
and squirrels, by flowing water and by human activities. In
our areas, seeds lie dormant for 20 months prior to
germination, and may remain viable for five years.
- How do I recognize it?
- In May it is the only plant in woods 1' - 4' tall
with white flowers
- Fruits are slender capsules 1 to 2.5 inches long
that produce a single row of oblong black seeds with
ridged seed coats
- First year plants have clusters of
3 - 8 kidney-shaped leaves at ground level
- First year
leaves have a wrinkles appearance and remain green
- Second year plants have small (1/4 inch)
white flowers with 4 petals. Blooms April through
- Second year leaves are triangular, 1 - 3 inches
wide, coarsely toothed on edges.
- Leaves give off a
garlic odor when crushed.
- Look alike plants. Violet leaves resemble
first year plants. However,
the violet flowers are low and have 5 petals. The
leaves are less crinkly.
Ground Ivy (Creeping Charlie) spreads along the ground as a
vine and has purple flowers.
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