Invasive Plants

Home » About » Invasive Plants

Spread the word, not the plant!

Warning to Boaters: Are you carrying an invasive aquatic plant on your boat, motor, trailer, or anchor? The most effective means of controlling invasive lake plants is through prevention and by educating others.

What you can do

• Clean all vegetation from your boat, motor, anchor, and trailer before launching your boat or leaving a lake.
• Dispose of plants on high, dry land away from the lake.
• Avoid driving your boat through any vegetation.

Good Plants and Bad Plants

Native aquatic plants

These provide many benefits to our lakes and ponds. These include:

  • Providing habitat to fish, insects, birds, and mammals.
  • Protecting shoreline areas from erosion by minimizing the force of wave action.
  • Limiting algae growth by competing for nutrients in the lake.

Invasive Aquatic Plants

These can be transported from one lake to another through boating activities. There is no known method of completely eradicating invasive aquatic plants once they become established.
Invasive aquatic plants have the potential to:

  • Displace beneficial native plants.
  • Harm water quality and reduce aesthetic appeal.
  • Negatively alter fishery habitat.
  • Ruin boating, swimming, and fishing.
  • Devalue waterfront property.

What to look for

Several invasive aquatic plants can cause problems for Maine lakes. Two species of Watermilfoil are a nuisance.

Curly Leaf Pondweed

Curly Leaf Pondweed

Potamogeton crispus

Confirmed infestation of West Pond in 2004. Is an aquatic perennial that begins growth in the fall, through winter and reaches maturity in early summer. It has submersed leaves that branch out as they grow. Turions form during their growth and drop off in early summer. Turions and rhizomes (underground stem) will sprout new plants in the fall.

Eurasian Watermilfoil

Myriophyllum spicatum

Is considered to be of greatest concern to Maine lakes. This plant is very aggressive and it spreads rapidly. It is found in all of the New England states except for Maine.

Variable Watermilfoil

Myriophyllum heterophyllum

Has been discovered in a small number of Maine lakes. It is a serious problem for lakes and ponds in New Hampshire, Vermont, and Massachusetts.


Caboba caroliniana

Found throughout the New England states. No plants have yet been reported in Maine. It is distinguished from the watermilfoils by the small white flowers that emerge from the water.

Water Chestnut

Trapa natans

Also found throughout New England. There have been no documented cases in Maine. this plant has characteristic triangular-shaped leaves and produces a spiny fruit.

Once these plants become established in a lake they are virtually impossible to eradicate!

Watermilfoil is an aggressive plant that can reproduce through fragmentation. A single piece can cause an infestation of an entire lake!
It grows at a rapid rate, which allows the plant to form large dense mats near the surface of the water. These dense mats make boating, fishing, and swimming difficult.

Maine is the only state in New England that is not infested by Eurasian Watermilfoil.

For further information contact:

Maine Volunteer Lake Monitoring Program
P.O. Box 445, Turner ME 04282
(207) 225-2070

This article is an excerpt from the “Stop the Spread of Invasive Aquatic Plants” flyer from VLMP.