The title may sound counterintuitive to some of us: why would anyone want to control or remove blackberry plants? Blackberries are a much-loved food—delicious, sweet yet tart, and useful in so many desserts and other dishes. And while many of us grow the plant intentionally, the blackberry plant can be an invasive weed in many parts of the world. From the west coast of the US and Canada to parts of Australia, some species of blackberry have become noxious weeds which crowd out native plants and invade yards, gardens, and landscaping. So if you live in Oregon, British Columbia, Queensland, Victoria, or any of the other places struggling with blackberry control, we’d like to offer some tips that might help and links to resources for more information. Let’s dig in and learn about how to control and remove blackberries when they become weeds.
Blackberries as an Invasive Species
Native to Eurasia, the blackberry plant comes in many forms, varietals, and species. As invasive plants, there are two varietals of blackberry that cause the most problems. On the west coast of the US and Canada, the primary culprit is Rubus armeniacus, popularly known as the Himalayan blackberry. As the scientific name suggests, this blackberry is native to Armenia and Iran, but has since been spread elsewhere both intentionally and accidentally. Intentionally introduced to California in the 1880s as a commercial crop plant due to its prolific berry production, Himalayan blackberry has since spread from the West Coast as far east as Wisconsin and Missouri—it’s classified as a noxious weed in both states. It is especially well established in the Cascades, causing problems for native plants and local gardeners in Oregon, Washington State, and British Columbia.
Meanwhile, our friends in the Southern Hemisphere are dealing with both Himalayan blackberry and evergreen blackberry (Rubus laciniatus) as invasives. The story is similar to North America: a well-meaning botanist introduced these plants in the mid 19th century. While they had potential as a commercial crop and garden plant, they quickly became noxious weeds. In Victoria and Queensland particularly, invasive blackberry contributes to a number of different issues: crowding out native plants and wildlife, providing habitat for other invasive species and diseases, erosion issues, and pasture loss.
In both North America and Australia, a number of agencies and a huge number of hard-working people are taking steps to limit the damage caused, but the presence of blackberry outside of its native environments is a stark reminder of how much damage an invasive species can do even when introduced with the best of intentions.
Controlling Blackberry in Your Garden or Landscaping
If blackberry is an invasive in your part of the world—or you’d just like to limit their spread in your garden or landscaping—there are a number of methods and approaches that may help. We encourage you to follow some of the links we’ve provided and check out the resources there; lots of smart folks are working hard on this problem and they’ve come up with some effective approaches to controlling blackberries.
· For landscaped settings, lawns, and agricultural land, mowing may be an option for blackberry removal. Frequent mowing removes the leaves and canes so that the plant eventually starves for lack of sunlight. The downside is that repeated mowing might not be appropriate for all settings and can damage the plants and soil we’re trying to save. Mowing blackberries is an approach that should be used judiciously, often in conjunction with other means of control.
· Goats and other livestock love blackberries, and may offer a “natural” mowing option in some spaces. Many areas have services that will “rent” you a herd of goats for the day so that they can eat away the unwanted plants on your property. However, like mowing this may remove plants you want to keep and will also add a great deal of “fertilizer” to your space.
· Mechanical removal—digging up blackberry plants, plowing them under, or a combination of the two—can be an effective method for controlling them. But the digging and plowing produces an area of freshly turned, fertile soil which can then host the next generation of blackberries from seed. If you’re using mechanical removal to control blackberry, make sure you’re keeping an eye on the site and taking further steps as needed.
· We generally don’t recommend herbicides, but in some areas and particular situations they may be the best option. We strongly encourage you to contact your local extension office or relevant authority to find out which herbicides work best in your region and the best and safest ways to apply them.
· For smaller spaces like garden and lawns/yards, paving stones and other hardscaping can limit the space into which a blackberry thicket can expand. If you’re in a place that permits you to grow blackberries, you may want to consider this as a way of keeping them contained and corralled. Alternately, many varietals of blackberry do well in containers. Container growing keeps them from spreading and makes relocating them much, much easier if the time comes.
Managing Blackberries
At Gardzen we firmly believe that there are no “bad” plants—just plants growing where we don’t want them or where they do harm to the environment. Blackberries are wonderful plants in the right place, and a huge problem in others. By taking appropriate steps to control and manage blackberries when they become invasive, we’re making not only our gardens better but the entire environment around them. Our actions resonate beyond our garden spaces, and by controlling and managing blackberry in your garden you’ll be helping the natural world of which our gardens are a part.
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