garlic mustard (Alliaria petiolata)
ODA rating: B
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 |  Images courtesy of Glenn Miller, Oregon Dept. of Agriculture
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| If images are downloaded and used from the ODA web site please be sure to credit the photographer. Description
Biennial; rosettes form by midsummer the first year, blooms May to June second year. Grows an average of one to three feet tall. Basal leaves dark green, kidney shaped, scalloped and two to four inches in diameter. Stem leaves alternate, sharply toothed, triangular, get smaller towards the top of the stem and produce a distinct garlic odor when crushed. Flower stalks usually single and unbranched. Flowers one quarter inch wide with four white petals that narrow at base.
Impacts
Garlic mustard displaces native forest under story species, reducing diversity and decreasing forage availability for deer. Frequently invaded habitat types include forest opening edges, roads, streamsides, trails and agriculture land; it thrives in the partial shade of oak savanna. Displacement occurs rapidly, often within 10 years of establishment. This plant is very difficult to control once established.
Distribution in Oregon
The first documented site in Oregon was 1959 in Multnomah County.  
Biological controls
No approved biological control agent is available at this time.
Informational links
Garlic Mustard printable trifold(pdf)
WeedMapper
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