Weeds: Hawkweeds – Hieracium spp.

• Family: Asteraceae (Compositae)
• Cycle: Perennial
• Plant type: Broadleaf

Biology

Hawkweeds are fibrous rooted perennial herbs that grow up to a foot tall. The leaves are basal, with an occasional leaf or two on stems. The bristly, leafless, flower stalks rise above the basal clump of leaves. The plants contain milky juice. They typically have five to thirty flower heads, and each flower has notched upper margins. Flowers may be yellow (yellow hawkweed) or red-orange (orange hawkweed). While mouseear hawkweed stalks typically bear a single yellow flower head (giving a dandelion-like appearance), the orange and yellow hawkweeds may bear several flower heads. These species spread by seed and creeping stolons which root into the soil. There are numerous species of hawkweeds. As they interbreed freely, it can be extremely difficult to identify them to a species level. SPECIAL INFORMATION: Depending on species, non-native hawkweeds are designated as Class ‘A,’ ‘B,’ or ‘C’ noxious weeds in WASHINGTON. Eradication or management of these species may be REQUIRED by law in your county. In OREGON, 5 species are designated as Class ‘A’ noxious weeds and three are target or ‘T’ weeds subject to priority prevention and control. Eradication or intensive control may be required in your county. In addition, several non-native hawkweeds are on the noxious weed quarantine list for both Washington and Oregon. Sale, purchase, and transport of plants, plant parts, and seeds is prohibited. Consult your local Noxious Weed Control Board for more information.

Habitat

Hawkweeds are found mostly in northeastern Washington, though several species may have limited distribution throughout much of the state. Yellow, orange, mouseear, and yellow devil hawkweeds can also be found west of the Cascades. Hawkweeds prefer coarse, well-drained soils in full sun to partial shade and are often found on roadsides, or in fields, pastures, or disturbed areas.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further germination.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• Apply according to label instructions.
• Use glyphosate products as spot treatments only!
• Not a problem in healthy established turf.
• 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.

Additional Images