Care of Floating Lettuce

Grow floating lettuce in USDA Hardiness Zones 9 through 11. Water lettuce will usually not do well any farther north.

Protect the floating lettuce from frost. Frost will burn leaves and the burned areas will then rot. Locate them in a sheltered area of the water such as under trees or next to walls. If frost is forecast, cover them with a tarp or bring them inside in buckets of water.

Position the floating lettuce in an area of the water that has partial shade in very warm climates during the hottest part of the day.

Keep floating lettuce plants crowded next to each other. Individual plants do not do well drifting around on their own. Make a corral by tying the ends of a length floating plastic tubing in a loop. Float the loop on the water and place the lettuce inside it. Another way of confining them is to bunch them together on the water's surface and tie a length of monofilament loosely around the sides of the bunch to create a sort of raft of lettuce plants. Landscape elements such as rocks will also work. Pile the rocks on the bottom of the body of water. Stack them to or past the water's surface to create a walled area under the water. Put the floating lettuce inside the walled area.

Keep fish from eating the roots of the floating lettuce if the fish largely outnumber the plants. A few fish with a large number of plants will be fine. Use a floating basket to protect the roots from fish damage. Buy a floating basket from a fish or pond supply store. A floating basket is a shallow, rectangular plastic box. When filled with water, the basket floats with the basket's rim at the surface. Float the basket on the water and place the lettuce inside it.

Feed your water lettuce if you notice the leaves turning yellow and the plants growing poorly. Float a few plants in a bucket of diluted plant food for a few hours. If you have a large pond with large numbers of plants, add a nutrient solution designed for the purpose.