Many of the state’s most serious invasive plants appear in home gardens as well as the open areas they rapidly dominate. Garlic mustard, multiflora rose, Asiatic bittersweet, Japanese barberry, Japanese knotweed and mugwort pop up and should be pulled by the roots when young.
But invasives that don’t make the state top-10 list are also huge headaches for gardeners. Some are true invaders. Others are planted with good intentions because of their fragrance, color, carefree nature or ability to cover the ground.
Wine raspberry (Rubus pheoniculasius). Often mistaken for raspberries grown intentionally, it flourishes in moist soil and is invasive in most of the eastern U.S. It can grow densely and its broad leaves choke out other plants. It spreads when canes touch the ground and root, and by seed. Use gloves to pull up by the roots and discard.
Ground ivy or creeping Charlie (Glechoma hederacea). Its listing as “potentially” invasive may be surprising to gardeners frustrated by this Eurasian native’s implacable incursions from lawn to garden. It puts down fresh roots every few inches, making control more difficult as it readily breaks off when pulled. Search for and disengage all the roots and discard.
Narrowleaf bittercress (Cardamine impatiens). It appears innocuous, slender and easily pulled, but small populations become dense thickets if not controlled early. This relatively recent invader prefers moist soil and some shade. Pull before it flowers and forms seeds.
Dame’s rocket (Hesperis matronalis). Fragrant white and pink flowers make this a happily tolerated invader and it continues to be included in wildflower packets. Check seed mixes to avoid planting it. Pull the plants before they set seed to prevent them from dominating shade gardens.
Goutweed, Bishop’s weed (Aegopodium podagraria). Often planted, especially variegated versions, as foot-high groundcovers in shady areas, it can be very difficult to remove. It spreads underground via rhizomes, and roots break easily when pulled. Dense cluster may need to be solarized to gain control.
Creeping yellow loosestrife, moneywort, creeping Jenny (Lysimachia nummularia). This attractive low-growing Eurasian native has appeal as a groundcover, with shiny green leaves and occasional bright yellow flowers. But in moist conditions it can form dense mats that choke out other plants. Keep it controlled by pulling from the roots.
Invasive Action!
A determined team of Invasive Plant Activists (IPAs) braved the initial drizzle and opened up an amazing vista through the cleared shagbark hickories along Day Street South on June 12. IPAs gather on the second Saturday of the month, 9 a.m. to noon. To learn more, send a note at GranbyInvasivePlants.weebly.com