Need help with your lake or pond?

Water Lettuce


Invasive - Eradicate!

Non-Native - no significant ecological benefits are known.



Water lettuce is a floating plant. This floating plant commonly forms large infestations which prevent boating, fishing and other uses of lakes and rivers. Water lettuce can form dense carpets of vegetation on the water surface, blocking sunlight from reaching submerged plants and reducing the oxygen exchange at the water's surface. It can also grow to form surface mats impenetrable to swimmers and waterfowl.

Plant Description

Water lettuce resembles a floating open head of lettuce. Water lettuce is a free-floating plant with many thick, spongy, dusty green simple leaves. The leaves are dull green, covered in very fine hairs, ridged and arranged in a spiral pattern from the center of the plant. The leaves are 1 to 6 inches wide and have large veins running their length. Water lettuce roots are light-colored and feathery. Its flowers are inconspicuous.

Hints to Identify:

Look for thick, soft, light green leaves (usually 6 inches in length) that form a rosette. The rosette conceals a small female flower and the seed-bearing fruit of the plant.

Homeowner Treatment Options
Shoreline Defense
*Aquatic Biologists recommends implementing preventative management techniques and physical removal prior to, or in conjunction with treatment.


Common Application Questions

Q. When is the best time to treat?

A. Once water temperatures are around sixty degrees or warmer.

Q. How often do I need to treat Water Lettuce?

A. Multiple treatments are generally required.

Q. How long before I see results?

A. It really depends on the product you choose. For most vegetation, control will take approximately 2 weeks however, tissue damage may be evident within 2 to 4 days with liquid formulations. Some products are slower acting with results taking 30 days or more to achieve.