Himalayan Blackberry
Rubus armeniacus
Washington State Classification
Class C — Widespread, County-Selected Control
It is a notorious invasive species in many countries around the world and costs millions of dollars for both control and in estimated impacts.
Quick Reference
Identification
Growth Habit
It is a rambling evergreen, perennial, woody shrub with stout stems that possess stiff, hooked prickles. It may grow up to 13.1 feet. Plants grow into impenetrable thickets.
Leaves
Leaves are alternately arranged on stems. Each leaf is palmately compound and made up of 3 to 5 (typically 5) leaflets with toothed margins
Flowers
Flower clusters (panicles) are flat-topped and have 5 to 20 flowers. Each flower has 5 petals that are white to rose colored and about 1 inch in diameter.
Fruit & Seeds
Flowers form blackberries—a grouping of small, shiny, black druplets that each contain one seed. Blackberries are about 1/2 inch to 7/8 inch in size.
Impact
It is a notorious invasive species in many countries around the world and costs millions of dollars for both control and in estimated impacts. This species spreads aggressively and has severe negative impacts to native plants, wildlife and livestock.
Ecology & Spread
Habitat
It can grow in mixed and deciduous forests and a variety of disturbed sites such as roadsides, railroad tracks, logged lands, field margins and riparian areas. It does well in a wide range of soil pH and textures. Please click here to see a county level distribution map of Himalayan blackberry in Washington.
Spread Mechanisms
Reproduction
It can reproduce by seeds and also vegetatively. Flowers can produce seeds with and without fertilization. It can vegetatively reproduce by re sprouting rootstalks, rooting stem tips and root and stem fragments.
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Control Methods
Cultural / Prevention
- Cultivation (rototilling or hoeing) will effectively eliminate plants. Mowing to prevent seed production is a very effective means of management. In lawns, mowing regularly at the proper height for the grass species may help minimize weed growth and invasion. Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further ger
Biological Control
- Success has been noted from grazing, especially by goats, yet sheep, cattle and horses may also be effective. This method seems to control the population from spreading and becoming larger but does not eradicate the plants from the site.