War of the Worlds author, H. G. Wells, once wrote: "Adapt or perish, now as ever, is Nature's inexorable imperative.” Some of Connecticut’s native plants may be on the losing end of this natural law as they wage a silent war of their own against rapid invasion by the exotic Japanese Barberry. The advance of this thorny intruder may even endanger our own health by providing breeding grounds for deer ticks, the prime carriers of Lyme disease.
Japanese Barberry (Berberis thunbergii) was originally discovered in Japan, where it safely co-exists with native plants. When, during the late 1800’s, it became increasingly popular to raise exotic plants, the Barberry found its way into gardens of New England. In those early days, it would have seemed unthinkable that such an innocent ornamental would come to take over vast areas of the Northeast and beyond.
In fact, Connecticut’s native species have been displaced at incredible rates by the Japanese Barberry. Seeds are dispersed largely by birds, which are very fond of the Barberry’s tiny, red fruits. Although birds can digest the fruit’s flesh, the seeds pass unharmed through their digestive tract. In this way, entirely new colonies of Barberry may sprout up wherever there are bird droppings, claiming areas once occupied by indigenous shrubs and wildflowers.
The Redding Pilot, a local Connecticut newspaper, reported in late 2009 that “there are about 170 [deer] ticks per acre infected with Lyme disease; where barberry is controlled, the total infected tick rate drops to 50 per acre.” It seems that wherever there is an abundance of Japanese Barberry, there is also an ever-growing population of deer ticks that carry infectious bacteria responsible for causing Lyme disease.
Some nearby states, namely Massachusetts and New Hampshire, have responded by prohibiting the sale and planting of Japanese Barberry in an effort to slow its advance. Connecticut has yet to impose any similar laws, but with the Japanese Barberry slowly crowding indigenous plants off the map, legislation may be just around the corner.