Much has been written on the subject of blackberries. As a plant we curse at it most of the year, and we callously hack, hew and wound ourselves to get rid of it, but nonetheless we delight in its fruit and will go after it with similar passion. One could make some interesting observations about human nature, looking at our relationship with this plant. It is nearing the peak of its "useful" period in our valley right now, with millions of fresh berries waiting to be claimed on vines in nearly every stream or neglected corner of the backyard.

What most of us don't know about this plant is that it is an exotic. Our common blackberry is actually the "Himalayan Blackberry", Rubus discolor. It is a native of Western Europe, not the Himalayan region of Asia. Like here, it was probably introduced in the Himalayas as a cultivated fruit. It appears to have arrived in the US around 1885, and by 1945 it was widespread throughout the west. As a pie lover I can say I've had fresh Himalaya-berry pies in the summer throughout the Western US. As a naturalist, I would have to say there are some problems with this.

The Himalayan Blackberry is member of the Rosaceae or Rose Family. Its close relatives include the raspberry and several species of blackberry, including a native California Blackberry, Rubus ursinus. Unfortunately though, the Himalaya-berry is far more aggressive and tends to smother native plants including berries, once it gets established.

The plant often begins as tiny seed in the droppings of a bird or other animal who has eaten the fruit. It typically germinates and begins to grow in the spring, and it needs plenty of light and moisture to establish itself. During this time it is easy to remove by hand, root and all.

Once it is established though, it quickly becomes tenacious. An individual plant can grow a cane up to twenty feet in a season, and its main cane forms branches. At the ends of these canes, new plants form and take root. These in turn can grow outward or grow back and re-enter the mass of canes. A single cane can thereby produce a thicket sixteen feet in diameter in less than two years. Even though an individual plant does not live more than three years, the dense thickets that are built up can last indefinitely. These have been measured at nearly fifty canes per square foot. These thickets tend to be a problem for native plants and for larger native animals who can lose access to water where the they grow. Fruit grows on second year canes, and then those plants begin to die while the thicket continues. New plants can also form at any point along roots, which can extend up to thirty feet under the ground, or even from a cane that has been cut. Meanwhile, a thousand seeds per square foot of thicket can be produced each year. While seeds have to struggle to germinate and take hold in the shade of the thicket they can do well beyond it, especially when passed though the digestive tract of animals. Seeds remain viable in the ground for several years.

As you might guess, removing blackberries is a topic of as much discussion as is cooking with them. Most sources suggest that the best way to remove the canes if you want to support other plants is to remove them manually, even though this may take several tries. There is no shortage of recipes for the fruits that come if you don't succeed.

For all our efforts to control these exotics, they are here with us in profusion--one more of the strange faces, and sometimes mirrors, of our natural world.