How to Grow Water Lettuce in Winter

The Pond Plant Girl Home Page


Water lettuce requires plenty of sunshine...
But in the wintertime, water lettuce has special needs. I presently keep my water lettuce and my water hyacinth in shallow plastic containers inside a greenhouse protected from frost and freeze.

Growing Water Lettuce Indoors
In cold winter conditions water lettuce can be wintered over indoors in a sunny window. However, it needs warmth and humidity. This can be accomplished with a Water Garden Light Box; such as the one pictured here. This light box was simply made with an aquarium located in a sunny window covered with clear plastic wrap (to keep in the humidity) and with mirrors inserted inside the aquarium to reflect the light. (The mirrors were scrap mirrors I obtained for free from a glass and mirror company.) The mirrors were inserted on the bottom and on the left and right sides of the fish tank. I tried growing water lettuce the following year without mirrors, and the plants did not survive.

Florescent Lighting
A florescent light must be placed on top of the aquarium to create heat and humidity. A grow light can be used to replace the florescent bulb and can be purchased online or at any hydroponics store. .

Growing Water Lettuce Outdoors
In the wintertime, if water lettuce is grown outdoors in a pond, it needs to be protected from freezing temperatures and covered with plastic or a Hoop House. However, it will also need a fan to circulate the air to prevent mold and mildew.

Here are some helpful links about growing water lettuce:
How to Grow Water Lettuce

Build a Water Garden Light Box

Questions?
If you have any questions or comments, please feel free to contact me at gail@pondplantgirl.com

How to Grow Water Lettuce

The Pond Plant Girl

Growing Water Lettuce
There are 2 types of water lettuce, Ruffled and Jurassic (also called the Amazon and the African). The Jurassic grow very large (as in the picture) and the ruffled is a smaller water lettuce with ruffled edges.

Water Depth and Quality: Water lettuce grows best in shallow non-moving water that is 1-2 feet deep. Although they are a free floating pond plant, they grow nice and large when their roots can reach down to the soil below and feed on the nutrients in the soil. The water pH should be 6 or 7.

Plant Maintenance: Caring for water lettuce in the warm spring through fall seasons is fairly easy. Cut back any decaying leaves. If you end up with a bounty of water lettuce, DO NOT toss it in a public waterway. There is a HUGE fine for plants dumped into public lakes, rivers, creeks, and streams. Water lettuce is a natural mulch. Instead, simply toss the extra plants in either a mulch pile or pile up under fruit trees. Your plants will LOVE you for it because the water lettuce contains fish emulsion that was absorbed while in the pond.

Hot and Cold Seasons

Summer Sun: Water lettuce normally thrives in any climate during the summertime. However, in very hot and desert climates the intense heat of the sun can fry the plants. I am located in zone 9 where it gets up to 115 degrees. The water lettuce that grew the best were the ones that received morning to noon sun.

Wintry Conditions: Frost is a killer. When water lettuce freezes it does not recover. When there is a threat of frost or freeze, water lettuce should be covered or brought indoors. However, remember that they do need sunshine during the day.

Water Lettuce Enemies

Mildew: It is wise to cover your pond to protect the water and plants from freezing. However, covering your pond will also promote mold and mildew growth on your water lettuce plants. This is also a killer and your water lettuce will simply rot away. If you plan to winter over your water lettuce. An indoor water garden lightbox is a good choice, or install a fan to circulate the air and keep the mildew away.

Aphids: It is also wise to "water" your pond plants each day, even though they grow in water. Bugs such as aphids will attach to your plants. By watering down your water garden each day, this will wash the bugs away and give the fish a little treat too.