Species specifics: Himalayan blackberry

Fast facts about Himalayan blackberry

Himalayan blackberry forms dense, thorny thickets that rapidly expand through root systems, seed dispersal and tip rooting, often crowding out desirable forage species and native vegetation.
Mature infestations can limit livestock movement, interfere with fence maintenance and reduce usable grazing acres by creating nearly impenetrable brush patches.
Common throughout the Pacific Northwest and coastal California, Himalayan blackberry thrives in disturbed areas, riparian corridors, pasture edges and unmanaged grazing ground.

What to look for

Himalayan blackberry (Rubus armeniacus), also commonly referred to as Armenian blackberry, is a non-native, highly aggressive shrub that is invasive and considered noxious in some parts of the United States.

This perennial blackberry species forms dense, thorny thickets made up of long arching canes that may reach 20 to 35 feet in length. The canes are thick, rigid and covered in large, recurved thorns that can hinder livestock movement, reduce pasture accessibility and interfere with fence maintenance and grazing distribution. Stems are often five-angled rather than round, which can help distinguish Himalayan blackberry from some native blackberry species.

Leaves are compound and typically contain 5 leaflets on first-year canes, though flowering stems may sometimes have only 3. Leaflets are dark green on the upper surface with lighter grayish or whitish undersides and serrated margins. Small white to pale pink five-petaled flowers appear from late spring through summer, followed by familiar blackberries that mature later in the season. While the fruit is edible and readily consumed by wildlife, birds and even livestock in some situations, the plant’s aggressive growth habit often outweighs its limited forage value in managed grazing systems.

One of the plant’s most problematic characteristics is its ability to spread rapidly through multiple pathways. Himalayan blackberry reproduces by seed, underground root crowns and rhizomes, as well as “tip rooting,” where trailing canes contact the soil surface and develop new plants. This allows isolated patches to expand into dense monocultures capable of crowding out desirable forage species and native vegetation.

As stands mature, old and new canes intertwine into nearly impenetrable masses of live and dead vegetation. In grazing pastures, these infestations can reduce usable acreage, limit livestock access to water or shade, create management challenges along fence lines and suppress perennial grass establishment through shading and competition.

Where it is found

Himalayan blackberry thrives in moist, well-drained soils and is commonly found along pasture edges, roadsides, riparian areas, irrigation ditches, fencelines, forest margins and abandoned fields. It readily colonizes disturbed ground and can quickly overtake unmanaged pastures or neglected grazing areas. In many areas, infestations are most severe where regular disturbance, grazing pressure, soil movement or reduced vegetation competition create opportunities for establishment.

Himalayan blackberry is often an indicator species of undermanaged or disturbed areas where woody encroachment is beginning to reduce forage productivity and pasture utilization. Early identification and management are important, as small patches can rapidly develop into large, persistent thickets that are expensive and labor intensive to reclaim.

Himalayan blackberry is now widely distributed across much of the western United States, with the heaviest infestations occurring throughout the Pacific Northwest and California. It is especially problematic in western Washington, western Oregon and coastal California, where mild temperatures, high rainfall and disturbed habitats support rapid spread.

Although most associate the species with the Pacific Northwest, Himalayan blackberry has expanded into additional regions of the United States and is considered invasive or noxious in numerous states. Isolated infestations can also occur farther inland along waterways, transportation corridors and urban-rural transition zones where birds and wildlife disperse seed.

How to treat it

Himalayan blackberry’s extensive crown system and vigorous regrowth can make long-term control difficult once large infestations are established. Foliar applications should be made after bloom in mid-summer to early fall before the first frost. Use HighNoon® herbicide at 16 fluid ounces per acre with Remedy® herbicide at 32 fluid ounces per acre plus a non-ionic surfactant at 0.25% volume/volume. Revisit treated sites as repeated applications may be necessary for large, mature populations.

Under normal field conditions HighNoon® is nonvolatile. HighNoon has no grazing or haying restrictions for any class of livestock, including lactating dairy cows, horses (including lactating mares) and meat animals prior to slaughter. Label precautions apply to forage treated with HighNoon and to manure and urine from animals that have consumed treated forage. Consult the label for full details. HighNoon is not registered for sale or use in all states. Opensight® has no grazing or haying restrictions for any class of livestock, including lactating dairy cows, horses (including lactating mares) and meat animals prior to slaughter. Except for lactating dairy animals, there are no grazing restrictions following application of this product. State restrictions on the sale and use of Remedy® apply. Consult the label before purchase or use for full details. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions.