This Himalayan Balsam or pink jewelweed on Bray Hill is being monitored and will be destroyed before it produces seed pods. Submitted photo
PHILLIPS — Invasive plants are no joke, and one such plant has been found on Bray Hill in Phillips. Known as Ornamental Jewelweed, Himalayan balsam, Pink jewelweed, its genus is Impatiens glandulifera. According to the Maine Department of Agriculture, Conservation and Forestry (DACF) the plant prefers moist soils but can grow in a wide range of soils and at higher elevations. It is common in riparian zones (stream and river shores), swales, and wet ditches along roadsides.
It is a very large plant, ranging from three to six feet or taller and its flowers are similar to Spotted jewelweed (Impatiens capensis) and pale jewelweed (Impatiens pallida), which are considerably smaller, have alternate, coarsely toothed, oval leaves, and orange and yellow flowers, respectively. It is native to Pakistan, India and Nepal, arriving here ion the U.S. by way of human introduction
Description: Herbaceous annual. Tall, up to 6½’ tall. Leaves: Simple, long tapering, pointed, 2-9″ long and serrate; occurring opposite or in whorls of 3. Flowers: Conspicuous, large (1-2″), bilaterally symmetrical, pink to purple flowers are helmet shaped and appear from midsummer into fall.
This species may attract bee pollinators away from native plants. Fruit: Seed pods are ¾-1½” long, taper at both ends, and contain 4-16 seeds. Like other “touch-me-nots” in the genus Impatiens, ripe pods explode when disturbed, ejecting seeds as far as 15′ from the plant. Stem: Sturdy, hollow, and smooth; greenish to red.
Maine DACF recommends hand pulling, weed-whacking, or mowing before flowering. Note that stems not uprooted can re-grow from nodes and still produce flowers and seeds. Monitor weed-whacked or mowed sites and repeat treatment as needed to prevent flowering. Sheep and cattle will graze it.
Pulled plants with flowers should be bagged as trash because seed pods can continue to develop if plants are left on the ground. Fallen plants can also sprout shoots and roots from stem. Foliar spray of glyphosate is effective when applied before flowering. If population is in a grassy area, use triclopyr, as it will not kill grasses.
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