Sunday, September 13, 2009

Another Invasive in the Adirondack Garden

“What have you got that the deer won’t like?” I asked the dude at the garden place. This was my favorite nursery, and over the years I spent hundreds of dollars there. I liked the people, I loved their display gardens, and their plant selection was terrific. Unfortunately, they included several invasive species in their stock and promoted them for garden plantings.

“The Japanese Barberry would be great – we have two colors, green and rose. The rose-colored one will look great next to your pale yellow house.”

“Isn’t it invasive?”

“Not up here.”

If a nurseryman tells you something you suspect is invasive “isn’t up here,” you should begin to question his motives. I don’t blame the man too much; after all, his job was to sell plants. Still, I’d like to think that folks who run plant nurseries would have an ecological conscience and would not go out of their way to promote the propagation of invasive species.

But, taking him at his word, I purchased two rosy barberries and planted them at home. They grew, provided nice contrast in the gardens, and the deer left them alone. Life seemed good.

Then a couple years ago the Adirondack Park Invasive Plant Program people put out the word that Japanese barberry (Berberis thunbergii), among other plants, were planta non grata – not only should we not be planting them (even this far north), but we should be going out of our way to eradicate them. This is because once established, the barberry starts to spread. In part this is accomplished vegetatively, but wildlife also help out. Sure, the plant may be deer-proof, but birds (such as ruffed grouse and turkey) and small mammals do enjoy the berries, and as you can see in the photograph, the berries are numerous. Once ingested, the berries get pooped out and sewn about the woods and open places, and since the plant is both sun and shade tolerant, it does well just about any place it lands.

Japanese barberry was first introduced to the US in the late nineteenth century as an ornamental planting at the Arnold Arboretum in Boston, Massachusetts. Soon it was being promoted as the plant to plant instead of European barberry (B. vulgaris), also an exotic. The latter was popular among early settlers as a hedgerow (keep the cattle and sheep in, keep the deer out), but also for dyes and jams. Unfortunately, it was also the host of a disease that did serious damage to wheat crops, so finding an alternative was welcome.

Today you find plantings of Japanese barberry everywhere, especially in median plantings around parking lots. I suspect this has less to do with keeping the deer from eating them than it does with keeping people from walking across these mini-gardens. And every one of these bushes is producing seeds galore, which all the birds are eating and distributing, potentially spreading the plant into the countryside where it can take over our remaining open spaces, its dense clusters readily pushing out native vegetation. Not only that, but Japanese barberry has been known to alter soil pH, nitrogen levels, and even disrupt the soil’s biological activity. All in all, it is a bad character.

Fortunately, removing barberry is fairly easy, provided it hasn’t grown too tall (they can reach eight feet in height). All you need is a pair of thick gloves and a good shovel. The plant has a fairly shallow root system, so some judicious loosening of the soil around the roots should make it easy to pull out. You want to be sure to get all the roots, for they can resprout. Should you miss some of the roots, you have a couple options. The easiest is simply to keep mowing down (or pulling out) anything that resprouts. The other is to treat the new stems with an herbicide, such as glyphosate, but this should be used a last resort, keeping in mind that such toxins are non-selective and will do in other plants as well.

Now, I know what you’re thinking. Once you remove the offending shrubbery, you will have a gaping hole in your landscaping. This is not visually appealing, so you may be reluctant to remove the invader. Well, fear not! There are plenty of native plants that you can use to replace the interloper: spicebush (Lindera bensoin), swamp rose (Rosa palustris), pasture rose (Rosa carolina), native gooseberries and currents (Ribes Americana, R. cynobati, R. lacustre, R. triste), northern bayberry (Myrica pensylvanica), ink-berry (Ilex glabra), winterberry (Ilex verticillata), and arrow-wood (Viburnum dentatum), to name a few.

So go on out and patrol your property. If you find a barberry, cut its life short. You’ll be doing the landscape, and the wildlife, a favor, especially if you replace it with a native shrub that produces berries that the locals enjoy.

Related Stories


Stories written under the Almanack's Editorial Staff byline are drawn from press releases and other notices.

To have your news noticed here at the Almanack contact our Editor John Warren at adkalmanack@gmail.com.




Comments are closed.