Himalayan blackberry (Rubus discolor) is a shrub with evergreen leaves that have 3 to 5 oval leaflets that are shiny green on top, pale green underneath with curved prickles on edges of leaflets.
Himalayan blackberry was introduced from Eurasia. Himalayan blackberry thrives in rich soils in old fields, along roadsides, in untended gardens, (and poking into even well-tended gardens from back alleys) and along streambanks. In the southern Sea to Sky region, expansive thickets of this shrub are obvious along the highway and in parks and green spaces.
It grows extremely aggressively, with new canes reaching out to several metres from the original plant. When these canes reach the ground, they can take root and in so doing, can “leap-frog” across an expanse of land in very few years if not kept in check. The canes are also very thorny.
The best method is to cut it down, then to grub out the root-crowns using a pickaxe or shovel. Blackberry will likely re-emerge in subsequent seasons, therefore blackberry removal is a two- to three-year commitment (depending on how long the shrubs were there and how large the seed bank is). In some situations, blackberry can be mown and mulched using farming equipment.
Himalayan blackberry is a mostly evergreen perennial with nearly erect stems that clamber and sprawl when they grow long; they can reach up to 35 feet in length. Stems have strong, broad-based spines that hold on tenaciously and older stems are five-angled. Leaves usually have five oval leaflets, bright green above and gray to white beneath. Small flowers are white to pinkish. The fruit is a juicy, edible blackberry up to half an inch thick.
These other blackberry species are less abundant than Himalayan blackberry.
Cutleaf blackberry (Rubus laciniatus) is also a problematic invasive plant. Leaves are usually made up of 5 very divided and toothed leaflets.
The native blackberries generally have weaker vines and tend to crawl along the ground.
Note the very divided leaves