Invasive Species vs. Non-Invasive Alternatives: Part 2

Contributed by Curtis Hawley

In Part 1 of this blog series, we talked about what the term invasive means in regard to plants. Another term that’s commonly used in this discussion is “native,” which refers to a plant that is native to the local environment. This term also can be dissected, argued and debated.

When we say a plant is native to our area, though, how far back are we going? When we go back about 12,000 years to the end of the last ice age, the glaciers that rolled down Route 128 almost certainly obliterated all “native” vegetation up to that point and transplanted them undiscerningly along its way. Let’s put a closer parameter on time: the Pilgrims landing at Plymouth Rock will be our time cap. We have pretty good documentation about the plants that inhabited our area at that time and those that were introduced for various purposes.

Let’s get into another exciting plant showdown, shall we?

Round 2: Japanese Barberry (Berberis thunbergii) vs. Cotoneaster horizontalis

Japanese Barberry & CotoneasterInvasive: Japanese Barberry (Berberis thungerii)

Japanese Barberry is commonly requested – it be quite appealing to the eye! Visual appeal is typically what spurs a non-native plant’s introduction to an environment. Since Japanese Barberry is an invasive species, it can handle all sorts of difficult conditions including deep shade. It can thus outcompete native plant species, dominating edges of woodlands and choking out native undergrowth.

Non-Invasive Alternative: Cotoneaster horizontalis  

There are a few great alternatives to Japanese Barberry, but my choice would have to be the Cotoneaster. If you want a taller form, Cotoneaster divaricatus looks very similar but grows to about 6’ – 8’. I think the Cotoneaster has a very interesting, unique structure. This shrub offers a skilled pruner (ahem) all sorts of possibilities to accommodate a client’s style preference; from formal and tidy to a natural and flowing look to even accommodating water features.

While Barberry’s deep burgundy color certainly gives it much fall appeal, Cotoneaster has game too! Its foliage has a similar burgundy show, although not quite as deep a color. Where it really wins in my opinion is its bright red-orange fruits which appear in late summer and persist into early winter. I’d recommend Cotoneaster to anyone interested in a Barberry with the confidence that they’ll be pleased with its unique look.

Cotoneaster horizontalis

Here are some other great advantages of this non-invasive alternative:

  • Very hardy plant in all sorts of conditions
  • Much broader, year-round interest
  • No thorns! Barberry is thorny, a concern for little ones, 4 legged friends and your local fine gardener tending your gardens
  • Rabbit problems? Cotoneaster is seldom abused by rabbits

In the next and final round of our Invasive vs. Non-Invasive showdown, we’ll highlight a plant not yet technically identified in Massachusetts as an invasive species. Intrigued? We’ll discuss alternatives before it’s classified as such!