Himalayan blackberry produces juicy, plump fruit. When managed and controlled in a small backyard garden, or in a park, the plant is a great food source for humans and birds alike.
However, this plant has a fruiting timeline limited to only a few months out of the year. Birds and other local wildlife populations need a diverse and reliable palette of plants to choose from as a source of food throughout the whole year. But Himalayan blackberry’s aggressive growth pattern can overtake a native forest or riparian understory in a matter of years, resulting in the disruption and reduction of other important food sources.
Blackberry also rapidly grows along trees near streams and rivers, causing those trees to eventually die from lack of water, nutrients, and sunlight. This invasion results in streams and rivers lacking sufficient natural tree cover to shade from direct sunlight, which then increases water temperatures. With increased water temperatures, juvenile salmon and other local fish species are less able to survive. Uncontrolled growth of Himalayan blackberry ultimately contributes to the problem of decreasing salmon populations in Washington State.