Non-Native Invasive Plant News & Updates

Photos are courtesy of L. Mehrhoff / Invasive Plant Atlas of New England (IPANE) or United States Department of Agriculture (USDA); unless noted.

Japanese Knotweed
Japanese Knotweed looks quite exotic, with tall stems, huge leaves, and large, feathery-looking white flowers. It grows into a practically impenetrable thicket, especially along roadsides, including Hammond Pond Parkway.
Removal & Restoration in Olmsted Park
The Conservation Commission approved a project that restored the native stream bank and wetland plant communities in an area of Olmsted Park near Ward's Pond, by Pond and Chestnut avenues. The project area covers 1.33 acres in both Brookline and Boston. This area had been infested with non-native invasive Japanese knotweed. Japanese knotweed spreads quickly and crowds out native plant species, creating a thick near-monoculture that provides little benefit to wildlife or the rest of the ecosystem.

The Emerald Necklace Conservancy, a local non-profit organization, initiated this project and worked with a consultant to appropriately treat and remove the Japanese knotweed, to significantly decrease or eradicate the knotweed. Revegetation with appropriate native species was undertaken by the Emerald Necklace Conservancy.

Replanting also enhances the reemergence of those native species that are found in the project area. The overall goal for the site was to enhance both biological diversity and wildlife habitat values. The project began in fall 2011 and is continuing for several seasons, during which time the Emerald Necklace Conservancy will continue to monitor and maintain the site.

Mile-A-Minute Weed Alert
Mile-a-minute weed, or Asiatic tearthumb, is an herbaceous, annual, trailing vine that has been found in many states on the east coast of the United States, including several communities in Massachusetts. Mile-a-minute weed has not been found in Brookline at this point, but is a significant concern for the town.

This invasive plant has light green colored leaves that are each shaped like a triangle as well as circular basal leaves, and the stems and undersides of leaf blades are armed with recurved barbs. Mile-a-minute weed grows very rapidly, covering shrubs and other vegetation and eventually killing these plants and reducing native plant species in natural areas. It can also be problematic for nurseries and horticulture crops. In addition to its extreme growth rate, this invasive plant has seeds that last for many years and are very persistent.

Mile-a-minute weed has little to no benefit to the environment here. Please keep an eye out for mile-a-minute weed in Brookline and your community. Early detection and removal of non-native invasive plants is 1 of the best ways to prevent their establishment in this area.

Mile-A-Minute Weed Foliage
Photo courtesy of Leslie J. Mehrhoff, University of Connecticut,
Lily Leaf Beetle Alert
The lily leaf beetle (Lilioceris lilii) is a non-native invasive insect that destroys native, as well as Asiatic, lilies. The beetle primarily feeds on lilies and Fritillaria and also feeds on a number of other plants, but only lays eggs and develops on lilies and Fritillaria.

The lily leaf beetle is native to Europe and was accidentally introduced through imported ornamental lily bulbs. The beetle is now found in Massachusetts and throughout New England, and is a major pest causing significant damage to native lilies.

Adult beetles are bright red with black head, legs, antennae, and underside, and are about 1/2-inch in length. Both adults and larvae will feed on foliage, with the larvae causing the most damage. Lily leaf beetles are active throughout the growing season.

Lily Leaf Beetle
Photo courtesy of University of Rhode Island
Garlic Mustard
Garlic Mustard was brought to North America by colonists who savored the spicy greens early in spring. It grows knee-high, attracts bees and butterflies, has beautiful white flowers and crowds out almost any other plant life - even lawn grass - as it spreads across the spring landscape.

Garlic Mustard
Black Swallow-Wort
Black Swallow-wort is a relatively recent established non-native invasive that is causing concern in Brookline. This vine, with shiny leaves and seedpods that look like milkweed pods, has been popping up in yards, hedges, and weedy places. Its seeds travel by air. It quickly overspreads an area, and re-sprouts from the roots after it is cut. Worse, where milkweed does not grow, Monarch butterflies may lay their eggs on Black Swallow-wort, but those larvae do not survive to adulthood.