The weed war: it's on
It's a rather personal question: Got any invasives in your back yard? There are 97 plants classified as invasive, or potentially so, by Connecticut's Invasive Plant Council, a nine-member appointed body created in 2004.
While most of us probably don't know the plants by name or sight, many have become the harbingers of spring along our roadsides and in scrub areas: clumps of Japanese Knotweed getting taller by the hour, the multiflora rose and ubiquitous Asian bittersweet leafing out.
"Invasive plants are certainly a concern throughout Connecticut; we are taking steps to learn about them, to take action and in some cases replace them," says Donna Ellis, a UConn extension educator and co-chair of the Connecticut Invasive Plant Working Group. The state-wide group of volunteers, from state agencies and UConn to land trusts and individuals doesn't have mandated authority over regulating invasive plants. It seeks to educate residents and raise awareness.
This is a good time of year, Ellis points out, to brush up on plant identification and figure out strategies to tackle the intruders, one yard at a time.
"If we can keep the invasives at bay, we can allow the natural species communities to thrive and maintain diversity," she says.
What makes a plant invasive? Similar to other species, from Asian shore crabs to pythons, it means not being native to the area but thriving in multiple locations and habitats, especially in the wild, woodlands or meadows, or disrupted environments, at the expense of the rest of the ecosystem. They are prolific reproducers, often through seeds, roots or rhizomes, and have few predators here.
Yes, many of these plants were brought in by government programs, as well as commerce, and did their job of colonizing all too well. Some are pretty - or so we once thought.
Potentially invasive plants can still be cultivated and sold in the state, but generally they are under study or observation by UConn and other agencies and eventually could be banned.
"Japanese Barberry can still be sold in Connecticut, but after research was done by UConn, the Connecticut green industry voluntarily decided to phase out 25 of the cultivars or varieties that produced the most seed," Ellis said. "Those plants will be phased out as of June 2013, but other cultivars can still be sold."
Massachusetts has already banned Norway Maple and Japanese Barberry, following a three-year phase out of nursery stock a few years back.
The state's nursery trade also has agreed not to market porcelain berry, a fast-growing vine deemed as potentially invasive. Popular because of its shiny blue berries, it still can be mail-ordered from out-of-state nurseries and plant catalogs. The much over-planted burning bush, or winged Euonymus, also remains in trade.
The newest bad actor, mugwort, Artemisia vulgaris, also called common wormwood, made the list last October. The very aggressive herbaceous perennial spreads by rhizomes and runners, grows 3 to 6 feet tall and thrives in uncultivated areas such as roadsides. It looks and acts like a weed.
As for getting rid of invasive plants, Ellis recommends pragmatism and understanding the botanical foe. The options are mostly mechanical removal or chemical control. There are few introduced biological controls. Timing is key.
"You need to know where the plant is in its life cycle," she says. "One of the big challenges is to use the correct control and to stay with it for a couple of years. You may be successful cutting down a plant the first year, but seeds and plant parts left in the soil will generate future years of new plants."
At this time of year, many of the invasives, such as the six varieties of honey suckle, can by pulled up in their vegetative state and left to die. Once the plants produce seeds, these shouldn't be left out or composted; burning may be the best option, but trash collection and incineration rules vary by town.
It gets trickier with the plants that actively spread through roots. Take Japanese Knotweed, an Asian relative of asparagus, the tender sprouts of which are highly regarded as a spring vegetable in Japan and increasingly by American food foragers. In the 1880s, Frederick Law Olmstead and other American landscape experts introduced it as a great roadside plant; now the 10-foot-tall groves of prolific plants are choking out everything else.
Half-hearted pulling only encourages regrowth of remaining roots. Instead, the plants need to be cut back to the ground at least three times in a year to starve roots and rhizomes, and the clippings bagged and disposed of.
Ellis says the state continues to track "Mile-a-Minute vine," an aggressive annual vine that has been found in six counties, including New London, and 32 towns. Photos are online and residents are asked to report findings by filling out an online form at http://www.hort.uconn.edu/mam.
The sprawling vine, with distinctive triangular leaves, backward-facing barbs or prickles on skinny stems and characteristic small saucer-shaped leaves called ocrea at nodes and branching points, can grow 6 inches a day and choke out underlying vegetation.
"It's rearing its ugly head all around the state; it's very aggressive and clambers over other plants," Ellis says. "You can hand-pull it early in the season and try to out-compete it with other plants. It's very easy to pull, especially young, but you'll need gloves because of the thorns."
The full listing of plants considered invasive or potentially so is available at http://www.cipwg.uconn.edu.
Donna Ellis is Suzanne's guest this week on "CT Outdoors" on WLIS 1420 AM & WMRD 1150 AM, live from 12:30 to 1 p.m. Tuesday or listen on demand at www.wliswmrd.net.
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