Water lettuce are a free-floating tropical plant with many spongy, dusty green simple leaves. The leaves are covered in very fine hairs and arranged in a spiral pattern from the center of the plant. Some people also refer to it as water cabbage.
The leaves are 1 to 6 inches wide and have large veins running their length. The flowers are seldom seen. Water lettuce is a very aggressive plant and can form thick floating mats.
Like the water hyacinth, the lettuce is fantastic at removing excess nutrients, shading the water and giving baby fry a safe place to hide. Adults will redily spawn in the long roots.
Water lettuce is a tropical plant that we treat as an annual. They are next to impossible to over-winter and should be tossed in the compost at the end of the season.
Water lettuce should be controlled so they do not cover the entire pond. 50-70% surface coverage is ideal.