The Thorny Story of Blackberries

Anna Brones, KP News Photo: Anna Brones, KP News

Is there a fruit that embodies Pacific Northwest summer more than the blackberry? This time of year, the blackberry is everywhere, and it’s an all-sensory affair.

We smell the fruit warmed by the summer sun and see the brambles plump with dark purple fruit. We stretch our hand in, feeling the poke of a few thorns as they dig into our skin. We hear the small cry that results, but push through, grabbing the fruit and popping it into our mouth, savoring that fleeting taste of summer. Payoff for a prickly business.

But this abundant, iconic, Pacific Northwest fruit comes with a complicated story. Here in the Pacific Northwest, we encounter three types: Rubus armeniacus, Rubus laciniatus and Rubus ursinus. Unfortunately, only one of them is native.

Rubus armeniacus, also known as the Himalayan blackberry, is the one that elicits our love/hate relationship. Despite its name, the species originally hails from Armenia, and if you have seen a blackberry bush in the last 24 hours, chances are it’s this one.

The stems, also called canes, are enormous, and immediately take over wherever they grow, reaching upwards of 13 feet high. Canes extend outward, stretching as far as 20 to 40 feet, taking root as soon as the tips hit the ground.

Despite its plump, flavorful fruit, in Washington state the Himalayan blackberry is listed as a Class C Noxious Weed (which means that control is recommended, but not enforced). Rubus laciniatus, the Evergreen blackberry, is on the same list, a blackberry whose leaves are comprised of five leaflets, all dark green and very spiky and jagged-looking.

The native species, Rubus ursinus, is found predominantly west of the Cascades and goes by many common names, including California blackberry, Douglas berry, trailing blackberry and Pacific blackberry. The stem is more delicate, trailing along the ground and into shrubs and small trees. Its leaves and thorns are smaller than the Himalayan blackberry; each leaf is made up of three smaller leaflets with jagged, sawtooth edges.

The native blackberry is too often dominated by the introduced varieties, and while the fruit of the Himalayan blackberry is delicious, its impact is less glorious. Its impenetrable thickets can outcompete native plants and tree seedlings, as well as habitat for wildlife.

How did the Himalayan blackberry get here? To answer that question, we have to go back to the late 1800s, when a man by the name of Luther Burbank was hard at work in Santa Rosa, California, breeding plants to create new varieties of fruits and vegetables.

Born in Massachusetts, Burbank had no formal training, but he had a keen interest in horticulture, which at the age of 21 had led to the purchase of a farm. It was here that he began experimenting with plant-breeding.

During his career, Burbank developed more than 800 new strains and varieties of plants. He set out to do the same for blackberries, looking to create a tasty berry that grew without the pesky thorns. In the course of his work, he purchased a packet of blackberry seeds that he mistakenly thought were collected in India. The fruit grew big and juicy and Burbank named it the Himalaya Giant.

Burbank hoped that this new blackberry would allow people to easily grow luscious fruit in their own backyards, and in the late 1800s, he began selling his new seeds in the mild climate of the Pacific Northwest, where the plant flourished. The rest, as they say, is history. The cultivated blackberry crop took over the region and eventually earned its status as a noxious weed.

Native blackberries are a rarer sight. While the Himalayan blackberry is bold and aggressive, tall and noticeable, the native ones are more reserved. Their stems are slender, the fruit smaller. The berries are smaller and sweeter, their flavor a little more intense than the cultivated variety; they even ripen a little earlier. They have been used by native cultures across the region for centuries, eaten raw, cooked, dried leaves turned into tea, and even used for more medicinal purposes like aiding stomach and digestion issues.

So what do we do with Himalayan blackberry? No matter how much you love the taste of summer, it is a noxious weed, and as such, it should be removed. The Pierce County Noxious Weed Control Board recommends using an integrated-pest-management (IPM) approach to noxious weed control. IPM is the use of a combination of all suitable weed control methods that not only match the management requirements of each site but also minimize negative environmental, economic and social impacts.

The easiest method is to address seedlings or first-year plants, which can be pulled straight from the ground. Larger thickets will require a two-stage process, first removing the above-ground vegetation and then the roots.

Hand-pulling the roots can be easier right after it rains, when the soil is looser. Repeated cutting of above-ground vegetation, a few times a year, year after year, can be effective as well.

If you only have a small amount of time to devote to blackberry control, the best time to do so is when the plant starts to flower. Once an area is cleared, consider replanting with native species.

As most of us know, regardless of how much effort we put in to remove these nonnative species, they inevitably come crawling back. When they do, at the very least make use of the fruit that’s abundant in every backyard, every trail, every forest across the Key Peninsula.

It’s blackberry season after all, and while we might not win the war on fighting the brambles back, we can at least enjoy the fruit. Consider it an act of resistance.