Also known as: hedge garlic, sauce-alone, jack-by-the-hedge, poor man’s mustard, jack-in-the-bush, garlic root, garlicwort, and mustard root.
Garlic mustard is one of our region’s most notorious weeds. A single plant of can produce thousands of seeds survive for years. This allows it to quickly take over an area. Garlic mustard also changes the composition of local soils making it inhospitable for other plants. If you’ve spotted it in the watershed, do not hesitate to take action!
Description:
| Life Cycle: | Biennial (life cycle lasts two years) |
| Early Detection and Rapid Response species: | Yes |
| Height: | Up to 3 feet (1 meter) tall |
| Leaf Description: | During its first year, the plant forms a rosette with kidney-shaped, dark green leaves. During its second year, it produces triangular-shaped, serratedSerrated Having a jagged edge. leaves. Leaves have a strong garlic odor when crushed. |
| Fruit & Flower Description: | Flowers have four small, white petals in the shape of a cross. Each plant produces seed pods, called siliques. These pods contain up to 5,000 seeds. |
| Bloom Time: | April to June during the plant’s second year. |
Habitat:
- Garlic mustard grows in dense stands in riparian areasRiparian Areas Areas of land that occur along the edges of rivers, streams, lakes, and other bodies of water. and forest understories including, urban parks, woodlands, roadsides, and trails.
- It thrives in areas with partial shade and moist soil.
Impact:
- It monopolizes light, nutrients, soil, and space which displaces native plants and reduces wildlife habitat.
- It emits chemicals from its roots that prevent other plants from growing . This creates an environment that only it can grow in.
What we’re doing about it:
- Garlic mustard is a priority species for the Tualatin SWCD. Over the last decade, partners across the Tualatin River watershed have made tremendous strides in controlling it. Although we have made progress, there is still a long way to go.
- If identified within Washington County, a specially trained crew can come out and survey for it. If found, the crew will treat the infestation for free.
What you can do about it:
- The best thing you can do to slow the spread of garlic mustard is to report it to the Oregon Invasives Species Hotline.
- Mowing is not a reliable treatment. Plants will re-grow and produce seeds later in the season.
- Small patches can be pulled by hand. Be cautious if removing it in the summer. Once its seed pods have ripened, they can easily burst open and spread seeds to new locations.
- Making sure to remove the entire root system and throw away all plant material in a plastic bag in the trash— not your yard waste bin or home compost.
Look-alikes:
Creeping Charlie (Glechoma hederacea) is often confused with garlic mustard. Creeping Charlie does not grow as a rosette and grows as a vine that crawls along the ground.
Fringecup (Tellima grandiflora), a native groundcover, is frequently confused with garlic mustard. Both species occupy the same habitats – shaded streams and forest understories. Their leaves and low-growing stature are also similar. The best way to tell these two species apart is by examining their flowers, Fringecup’s flowers are bell-shaped.
Piggyback plant (Tolmiea menziesii) is another native look-alike. Piggyback plant also thrives in shaded streams and forest understories. It resembles fringecup but has purplish-brown flowers.
Noxious Weed Listing:
| State of Oregon: | Class B |
| State of Washington: | Class A |
More Resources:
Download the Garlic Mustard Best Management Practices Factsheet
- Pacific Northwest Weed Management Handbook: Garlic mustard
- University of California, Weed Research & Information Center: Garlic mustard