WSU Extension


Weeds : Blue mustard (Purple mustard, Tenella mustard) : Chorispora tenella
(revision date: 4/7/2021)

Family: Brassicaceae (Cruciferae)
Cycle: Winter annual
Plant Type: Broadleaf

Use Integrated Pest Management (IPM) for successful weed management.

Blue mustard is a leafy, taprooted winter annual. Plants branch primarily from the base, with some branching of the flowering stems, as well. The rosette leaves of seedling plants are deeply lobed or toothed. Mature plants are six to eighteen inches tall, with nearly unlobed leaves that are toothed or wavy. Flowering stems are leafy on the lower portions. Both leaves and stems are covered with gland-tipped hairs which make the plants feel sticky. The four-petalled flowers appear in early spring, and are purple to somewhat pinkish. Seed-pods are thin, slightly curved, elongate and seedless (sterile) for about 1/3 of their length. Unlike the seed-pods of many other mustards, which split open along the length of the pod at maturity, blue mustard pods break apart crosswise into two-seeded sections.
Blue mustard is a weed of fields and waste places. It is common east of the Cascades.

Management Options

Non-Chemical Management
  • Cultivation (rototilling or hoeing) will effectively eliminate plants.
  • Apply organic mulches, such as bark, compost, grass clippings, straw, and other materials, in a layer from two to several inches thick for effective weed management.
Select non-chemical management options as your first choice!

Chemical Management

Apply according to label instructions. Not a problem in established turf areas. Glyphosate products should be applied as spot treatments only! NOTE: Some ingredients listed here are only available in combination. Read the label carefully on combination products to make sure the product is suitable for your specific situation.

Landscape areas
  • glyphosate
  • dichlobenil
Turf areas
    Bare ground areas
    • glyphosate
    • dichlobenil
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    Caption: Blue mustard with flowers
    Photo by: J.A. Kropf
    Caption: Blue mustard with flowers
    Photo by: J.A. Kropf
    Caption: Blue mustard established in a field
    Photo by: J.A. Kropf
    Caption: Blue mustard rosette
    Photo by: J.A. Kropf