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 Meadow Hawkweed Complex, Hieracium pretense, H. floribundum, and H. piloselloides, have bright yellow blossoms that branch out near the top of erect stems. The leaves in basal rosettes are spatula-shaped. Both the leaves and stems are hairy, and the entire plant contains a milky juice. Only a few leaves are found on the stems, which can grow up to 3-feet tall. These noxious weeds form mats that choke out other plants. The seeds pods blow in the wind like small dandelion puffs.
Several native hawkweeds grow in the Swan Valley. They have smaller white or pale yellow blossoms. The natives don't form mats and don't crowd other plants. Learning to identify the natives will save time and money spent on unnecessary spraying.
Meadow Hawkweed Complex (yellow hawkweed) Prevention
and Treatment
The noxious yellow hawkweeds (meadow hawkweed complex) should be eradicated as soon as they are located and before they form large patches. Learning to identify and map noxious hawkweeds is critical.
 Unlike knapweed, hawkweeds in the Swan Valley are still in small enough patches that the plants can be eradicated. They should be destroyed before logging or other activities involving heavy equipment. The hawkweeds will accelerate their spread in the disturbed soil. Clipping the seed heads can slow the hawkweeds' spread but is not sufficient to eradicate the plants. If only a few plants are found they can be dug up and destroyed. The site should be revisited for several years to be sure all the plants were removed. Hawkweeds are hard to recognize after the blossoms go to seed. Early summer is the time to look for hawkweeds in the Swan Valley.
Unlike knapweed, hawkweeds can grow under the tree canopy or out in the open. Once noxious hawkweeds are widespread, spraying with herbicides is the only effective option we know of. Herbicides should be applied by a trained applicator at the rates recommended by the product manufacturer. The best time to apply herbicides is when the plants are vigorously growing, usually in May, June or early July.
Any effective treatment should include re-vegetation with native plants or other desirable vegetation.
For more information visit Missoula County Weed District. |
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Swan Ecosystem Center
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U.S. Forest Service Condon Work Center • 6887 Highway 83, Condon, MT 59826
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| Office: (406) 754-3137 • Fax: (406) 754-2965 • Email: swanec@blackfoot.net |
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