The Devil's Weed

Richard Nixon had an enemies list, and so do I. Unlike Tricky Dick, my enemies are not political foes but plants. Specifically, the invasive Scotch broom and Himalayan blackberry. Both take advantage of disturbances and are persistent. My worst nightmare came true when I found a Scotch broom growing intertwined with a blackberry. I just know they were plotting against me!

Let’s start with Scotch broom. Native to Europe, this shrub with the ugly yellow flower came to America to fight soil erosion and brighten up roadsides. Once it took root, it took over. I’ve seen fields of it. Even a forest of old growth Scotch broom, trees 15 feet tall crowding out the native vegetation. It takes over grasslands and forest, causing habitat loss for the many critters who call grasslands and forests home. If eaten, it can be toxic.

Old growth Scotch broom- not too impressive but it's winter in this picture

Great, it puts nitrogen in the soil (it’s actually a member of the pea family), but what good is nitrogenated soil if no one else gets to use it? Seeds can remain viable in the soil for 80 years, maybe longer. Fire doesn’t destroy them; in fact, they may even benefit from fire since this weed loves a disturbed area. Constant pulling is the best way to control this fiend. Just don’t pull a muscle in your back like I did.

Scotch broom monoculture (from Bingham County, ID)

Himalayan blackberries may be even worse than Scotch broom. Blackberries can fight back. The canes are covered in thorns that make cutting them a chore that involves getting yourself cut in the process. The canes grow up, droop down, and sprout a whole new bush when they reach the ground. Each bush gives off thousands of berries, each with dozens of seeds. Birds, bears, raccoons, and who knows what else eat the berries and poop put the seeds, spreading more evil bushes far and wide.

The Himalayan blackberry is a failed experiment by food biologist Luther Burbank. Using selective breeding, he created varieties of fruits and vegetables that we still eat today. The Himalayan blackberry (which originated in Armenia) was supposed to be a thornless variety. Instead, it turned out to be perfectly adapted to life in the Northwest. It can grow just about anywhere and will cover anything in its path. The one pictured below (next to a tree) is at least 15 feet tall. I added a second picture with the entire tree visible, for perspective.

Himalayan blackberry under this Douglas fir

Left Douglas fir is the one seen above

When you are working on restoring a site to its natural condition, there will more than likely be at least one invasive plant. But it gets so frustrating when you have to clear the same plants year after year, especially when you know you got rid of them all the year before. Diligence and persistence are probably the two most important tools in any restoration ecologist’s kit.

Himalayan blackberry is just now beginning to bear fruit

Scotch broom greets me at my land trust property

Here's the variety with red on the flowers

Luther Burbank info came from this fascinating NPR article. The monoculture picture is from Bingham County, Idaho's noxious weed program.