Eurasian watermilfoil is a native plant to Europe, Asia and northern Africa. It is, however, non-native to North America. It is not exactly known when Eurasian watermilfoil came in contact with North American waters. There are various assumptions of how it got here, one of which is that someone brought it over from Europe as an aquarium plant. After it over took their aquarium, it was disposed in the yard and made its way into a watershed, spreadingfrom there. Another theory is that it was brought over in the ballast water of ships, on their way to the great lakes.


Eurasian watermilfoil is an extremely rapid growing plant. It can grow up to 10 inches in a weeks time. The roots of the plant are a distinct silver color that can root in an array of bottom types. It can and will grow in sandy, rocky bottoms but thrives in the more silty bottoms that are nutrient rich. The weed has numerous stocks that grow from its fibrous root system. The stocks will grow up to the surface, sometimes in 20 plus feet of water (Based on available bathymetry data, approximately 60% of Lake Dunmore, or 600 acres of the lake’s 985‐acre total surface area, are capable of supporting Eurasian watermilfoil growth).  The plant has 4 whorls of 4 feathery leaves around the stem. Each leaf is divided into paired leaflets, primarily 12-21 pairs per leaflet. The top of the plant is topped with a bright red crown. Individual stems branch out at the top of the plant when the plant nears the surface.

The plant spreads so easily and rapidly because it starts spring growth sooner than other aquatic plants, can live in both nutrient rich and nutrient poor waters, and reproduces through fragmentation. This means that any part of a stem that breaks off from a plant will float to other areas, eventually sink to the bottom, and start a new plant. Anything that disrupts the water, like outboard motors, can cause fragmentation and new growth. In late summer and fall, a period that coincides with greatest use of Lake Dunmore, the plants become brittle and even more prone to fragmentation.

Infestations rapidly expand and can take over an entire lake within two years of its introduction. Unchecked, it quickly forms a thick canopy that chokes out other plant-life and adversely affects lower food-chain aquatic life and eventually fish, reptile and amphibian predators. In addition to its effects on aquatic life and fishing, Eurasian Milfoil can damage outboard motors and hinders recreational boating and swimming.

Vermont law makes it illegal to transport Eurasian watermilfoil, along with  zebra mussels and water chestnuts, on boats and boating equipment. Any person found transporting any of these species to or from a Vermont lake or pond will be in violation of this law. Penalties for violations could include fines, imprisonment, or both (pursuant to 10 V.S.A. §1266).