- Orange hawkweed is a perennial plant native to the alpine regions of central and southern Europe
- Bright orange, orange-red, or yellow flowers with several flower heads in clusters
- Stems are usually single, unbranched and leafless; leaves are found at the base of stem in basal rosette formation (native hawkweeds will have true leaves all the way up their stems)
- Stems are covered in black hairs
- 0.3 – 1.2m tall
Consequences of invasion
- Invasive hawkeed species can replace native vegetation in open, undisturbed natural areas
- Reduce forage and threaten biodiversity
- Outcompetes forage plants in hay fields and pastures
Integrated Pest Management Options
- For small infestations, dig out rosettes and their shallow roots and dispose in clear plastic bags for free
- Do not spread any vegetative parts of the plant as regrowth can occur
- Mowing removes flower stems and may prevent seed set, it should be used with caution as it encourages vegetative spread
- Large infestations can be treated with high nitrogen fertilizer , try 34-0-0 granular nitrogen which is available from Nelson Farmer Supply.
- You can broadcast the fertilizer (3kg/200m2) or use spot treatment (approx 5-12g of granular fertilizer per basal rosette).
- Treat AFTER a period of moisture rain or dew (water activated) but BEFORE a sunny period (so fertilizer doesn’t wash away). Also, treat BEFORE flowers set, otherwise you will need to remove seed heads
- Mortality and decrease in density will be visible within two weeks, however follow-up treatments are needed to get distribution down. Hard packed and sloped surfaces take longer to treat.
- Grasses will be boosted, as will other tap roots (knapweed, thistle), and over-fertilization can kill most things, including trees so be mindful of surrounding vegetation.
- Minimize soil disturbance and promptly revegetate disturbed areas
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