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

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.

Blue mustard plant

Typical plants growing in a disturbed site. Photo by W. Hanson Mazet.

Leaves

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

Blue mustard leaf

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

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.

Blue mustard flower

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

Roots

Grows a shallow taproot.

Blue mustard rosette

The rosette leaves are somewhat lobed. Photo by J. DiTomaso, UC Davis.

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, PDF.

CA Dept. of Food and Agriculture. No date. Blue or purple mustard, CDFA.

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, image.

USDA-NRCS Plants Database. 2011. PLANTS profile for Chorispora tenella, USDA.

Whitson, Tom D. (editor). 2002. Weeds of the West. University of Wyoming, Jackson, Wyoming.

Learn more about the author(s)

A Northern Nevada Homeowner’s Guide to Identifying and Managing Blue Mustard

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.

Blue mustard plant

Typical plants growing in a disturbed site. Photo by W. Hanson Mazet.

Leaves

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

Blue mustard leaf

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

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.

Blue mustard flower

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

Roots

Grows a shallow taproot.

Blue mustard rosette

The rosette leaves are somewhat lobed. Photo by J. DiTomaso, UC Davis.

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, PDF.

CA Dept. of Food and Agriculture. No date. Blue or purple mustard, CDFA.

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, image.

USDA-NRCS Plants Database. 2011. PLANTS profile for Chorispora tenella, USDA.

Whitson, Tom D. (editor). 2002. Weeds of the West. University of Wyoming, Jackson, Wyoming.

Published by: 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