Blue mustard plant

Typical plant growing in disturbed site. 

Blue mustard leaf

The leaves are somewhat spear-shaped and have wavy, toothed margins.
(Photo by W. Hanson Mazet)
 

Blue mustard flower

The purplish flowers occur in clusters at the ends of stems.
(photo by W. Hanson Mazet)
 

Blue mustard rosette

   The rosette leaves are somewhat lobed.

 

Other common names

Purple mustard, tenella mustard, bead-podded mustard, musk mustard.

Scientific name

Chorispora tenella

Family

Brassicaceae

Description

A leafy, branching plant growing up to 1 1/2 feet tall, blue mustard sprouts in the fall, growing a ground-hugging rosette form. It matures early in the spring, often before homeowners are aware it is present. Blue mustard is characterized by a strong, unpleasant odor. It is commonly found growing in groups rather than as single plants.

  • Leaves

    Alternately attached leaves are somewhat spearshaped to oval, somewhat toothed, and are covered with tiny. sticky hairs.

  • Stems

    Branch mostly from the base; sticky to the touch.

    Flowers

    Small, purplish flowers are about 1/2-inch across, with four petals in a cross shape. Blooms during the early spring. Seeds are produced in long narrow pods.

  • Roots

    Grows a shallow taproot.

Native to

Europe

Where it grows

Roadsides, vacant lots and dry, disturbed sites

Life cycle

Winter annual (sprouts in fall and flowers in spring)

Reproduction

Reproduces by seed; seed can be produced within 10 days of flowering.

Control methods

As with all annuals, preventing seed production is essential. Control before seeds are produced in the early spring.

 

  • Mechanical

    Cultivation is very effective in controlling this plant. Dig, hoe or pull young plants. Mowing during early flowering reduces seed production.

    Cultural

    Plant desirable vegetation to help suppress it. Thick mulches may be effective in reducing infestations.

    Biological

    None commercially available.

    Chemical

    Try broadleaf selective herbicides such as 2,4-D + dicamba on rosettes early in the spring. Dicamba can persist for several months and may damage desirable plants in the area treated. Glyphosate can also be used on rosette leaves but is nonselective and damages both grasses and broadleaf plants. Add a surfactant per label instructions to enhance uptake by the waxy leaves. Pre-emergence herbicides will help to manage existing seed banks.

References

Butler, M.D. 1994. Blue mustard. Pacific Northwest Extension Publication 471, http://ir.library.oregonstate.edu/concern/ administrative_report_or_publications/41687h68w

CA Dept. of Food and Agriculture. No date. Blue or purple mustard, http://www.cdfa.ca.gov/ phpps/ipc/weedinfo/chorispora.htm

DiTomaso, J.M. and E.A. Healy. 2007. Weeds of California and Other Western States. University of California Publication 3488.

Lyon, D.J., R.N. Klein and R.G. Wilson. 2006. Blue mustard control. NebGuide G1272, http://www.ianrpubs.unl.edu/epublic/live/ g1272/build/g1272.pdf

USDA-NRCS Plants Database. 2011. PLANTS profile for Chorispora tenella, http://plants.usda.gov/ java/nameSearch

Whitson, Tom D. (editor). 2009. Weeds of the West. University of Wyoming, Jackson, Wyoming.

Donaldson, S. and Hanson Mazet, W. 2011, A Northern Nevada Homeowner’s Guide to Identifying and Managing Blue Mustard, Extension | University of Nevada, Reno, FS-11-61
Printable    Version    (PDF)

Learn more about the author(s)

Wendy Hanson Mazet
Wendy Hanson Mazet
 

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