Why did blackberry brambles become such a NW problem?
Figure 1 Todd Wright with the blackberries he has trained in his backyard.
If you have property in the Pacific Northwest, there’s one plant you’ve most likely encountered … and battled – The Himalayan Blackberry.
It’s enemy No.1 in the Northwest. So, where did this plant come from and why did it become such a pervasive pain in the garden?
With tall, spiny stalks that can grow up to 40 feet in a season, the Himalayan Blackberry will quickly take over if left unchecked. And it has.
The Urban Forester for Seattle Parks, Mark Mead, is working on a 20-year plan to restore native plants to 2,500 acres of forested parkland in the city. He says 20 percent of the land is being choked by invasives, with Himalayan blackberries at the top of the list.
“It’s our number one plant in terms of the volume of invasive species that we have,” Mead says. “You can see how fast the blackberry comes into the area, and it’s taking over the site.”
Remember the large nodules
Brandishing a shovel on the edge of a blackberry thicket in Kinnear Park, he says the most effective way to get rid of them is also the toughest. You have to chop the brambles back and then dig out the roots by hand.
Figure 2 Mark Mead with Himalayan Blackberry roots dug up at Kinnear Park. (Photo by Bellamy Pailthorp)
If you miss the large nodules that are the storehouse of the plant’s energy, Mead says, it will quickly re-sprout and can push through several inches of mulch and even tarps or cardboard.
“It just doesn’t like to stop. It’s very tenacious. And so we just have to be more tenacious,” he says.
Restoring Seattle’s forests began in 2005 and will cost the city about $25,000 per acre, Mead estimates (even with about 88,000 volunteer hours per year). But he says it will also save the city millions of dollars on storm water infrastructure, as native trees and shrubs come back and absorb runoff.
Just clearing blackberries without grubbing out the roots can cost between $250 and $1,000 per acre.
A costly mistake
Why is so much green space – whether it’s in our parks or in our backyards – covered with this invasive species? How did it get here?
You could say it was a case of unintended consequences.
Back in 1885, the famous botanist Luther Burbank first brought the Himalayan Blackberry to the U.S. as a backyard plant.
Inhis field notes, Burbank enthusiastically describes its vigorous growth and abundant, extra-large fruit.
Figure 3 Luther Burbank (Photo from the Library of Congress)
“Everybody thought it was wonderful. No one was complaining about it,” says plant expert Arthur Lee Jacobson.He says native brambles, such as the trailing blackberry, with its gentler vines and smaller fruit, were considered ho-hum in comparison.
After birds and other animals began spreading the seed up the west coast, the Himalayan Blackberry became so popular, for several years it could not be multiplied fast enough to meet the demand. Then at some point, it got out of control.
Jacobsen says the man who brought us dozens of desirable plants - from Burbank potatoes and elephant garlic to Shasta daisies – also unleashed the Godzilla of invasive species.
“The Himalaya Blackberry, it was more successful than we liked,” Jacobsen says. “And now we have to deal with the consequences.”
A bully plant
Himalayan Blackberry is now classified as a noxious weed. It grows so fast and its roots are so powerful, it can erode riverbanks and destroy habitat for native species, such as salmon. In just over a century, it’s spread so far, it’s everywhere.
Sasha Shaw, with King County’s Noxious Weed Control Program, works fulltime educating the public about the dangers of invasive plants.
“And for some reason, these particular plants are really good at growing here in Washington, even though they didn’t evolve here, even though they’re not from here,” she says, adding that invasive plants, “are the ones that we call plant bullies.”
And the Himalayan Blackberry is one of the biggest bullies. Shaw says all they can do now is try to reduce its impact.
“We don’t have any hope of actually eradicating Blackberry from Washington,” Shaw says. “It’s here to stay. It’s part of our landscape.”
Love-hate relationship?
But for many people, that’s not such a bad thing. They say blackberries provide a unique connection to wild plants.
Recently, 4th-graders on a tour with Shaw shared fond memories of summer, foraging for the tasty fruit.
”We’d go swimming and pick blackberries. We’d fill our hands and our hands would be all stained,” says Jacob Monahan.
”I would go to this blackberry festival and pick blackberries from hundreds of bushes,” says Edvin Sanders.
“We would go to the dog park, but we sometimes didn’t really go there for the dog, we went there for the blackberries,” says Bella McCann.
And it’s not just the fruit. Even the thorny brambles themselves have their fans here.
Making lemonade out of lemons
Todd Wright is a librarian, who lives in Mukilteo. He was struggling to contain the blackberries that were threatening to take over his back yard. Then he got an idea.
“I thought well why not eventually just let them grow up and over and create like a tunnel? And so, that’s what you have here,” he says.
Figure 4 Sasha Shaw with 4th graders from Margaret
Mead Elementary (Photo by Bellamy Pailthorp)
Rather than fighting them, he has trained his blackberries to grow over a trellis. The thick growth forms a tunnel-like covered pathway to a fire pit that Wright describes as his escape from everyday life.
“There’s just something about them that seems sort of enchanting” he says of the brambles. “It just makes me think of like, Grandma’s farm and out in the back where only the kids go and where the fairies are. And it’s a magical place, where the blackberries are sort of the border between this world and the other world.”
But he admits that it takes a lot of maintenance. He tends to his yard pretty much every day, coaxing the blackberry vines to grow where he wants them and clipping stray canes. Left to their own devices, “they will just ramble on,” Wright says.
Pailthorp, Bellamy. "Why Did Blackberry Brambles Become Such a NW Problem?"KPLU "I Wonder Why...?"NPR. KPLU 88.5, Tacoma, Washington, 1 June 2012. Web. 10 Oct. 2014. <http://www.kpluwonders.org/content/why-did-blackberry-brambles-become-such-nw-problem>. Transcript.
Questions for article: Why did blackberry brambles become such a NW problem?
Directions: Answer the following questions in your science notebook (IQIA). Cite evidence from the article in your answers.
1. Why were Himalayan Blackberries introduced to the United States in 1885?
2. How did Himalayan Blackberries spread up the west coast following their introduction?
3. What are some negative consequences of Himalayan Blackberry’s introduction?
4. How is the introduction of Himalayan Blackberries to the northwest an example of “unintended consequences”?
5. What are some positive consequences of Himalayan Blackberry introduction?
6. Describe the solution to Himalayan Blackberry invasion that is described in the beginning of the article.
7. How much does it cost to clear Himalayan Blackberries (including and excluding root removal) from 1 acre of Seattle forested parkland?
8. What are the benefits of Himalayan Blackberry removal from Seattle forested parkland?
9. Is the solution described in this article sustainable? Explain your reasoning.
The following is an excerpt from the National Wildlife Federation website (http://www.nwf.org/wildlife/threats-to-wildlife/invasive-species.aspx):
“An invasive species is any kind of living organism that is not native to an ecosystem and causes harm. They can harm the environment, the economy or even, human health. Species that grow and reproduce quickly, and spread aggressively, with potential to cause harm, are given the label of “invasive”.”
10. Is Himalayan Blackberry an invasive species? Cite evidence from the excerpt above and the article to support your answer.