Water Lettuce Pond Plant - Care & Grow Guide
by Tory Jon | Last Updated: November 15, 2022
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Water Lettuce is often mistaken for a floating head of cabbage. This is understandable as both are similar in appearance and float on the water’s surface. It features ribbed and velvety foliage, usually in light green to lime-green color.
Water lettuce (Pistia stratiotes) was discovered 2000 years ago along the Nile River. The earliest documentation of the plant can be found in ancient Greek botanists’ writings and Egyptian hieroglyphics. They are everywhere – marshes, lakes, bogs – across all continents except Antarctica.
Pond and water garden owners prefer Water Lettuce because it helps keeps the water clean by preventing algae growth. It also absorbs heavy metal toxins, including cadmium and zinc, from water.
Invasive Potential: High. Water lettuce is Pistia stratiotes. The USDA National Invasive Species Information Center lists it as an aquatic invasive plant, and regional restrictions can apply to sale, possession, transport, planting, or release.
It can grow rapidly across the water surface in warm climates. Plant laws can change, so confirm current requirements with your state agriculture or natural resources agency before purchasing or planting it. Never release unwanted pond plants, roots, seeds, rhizomes, or trimmings into lakes, rivers, streams, wetlands, drainage ditches, storm drains, or natural ponds.
Scientific Name
Pistia stratiotes
Invasive Potential
High
Common Names
Water cabbage, water lettuce, Nile cabbage, shellflower, Pistia Stratioes
Plant Type
Floating plant
Light Requirements
Partial to Full Shade
Hardiness Zones
USDA 9-11
Bloom
Late summer to early fall
Grow Up To
12 inch spread
Flower Color
White, yellow
How To Plant Water Lettuce In A Pond
After buying your Water Lettuce in small groups or by the head, detach all yellow leaves in preparation for planting. The best time to plant is during late April when the last frost of the season has gone. To plant, spread the lettuce across your pond and ensure minimal movement.
Tip: Tie a fishing line around the bunch of water lettuce you placed in the pond to help keep them immobilized.
Despite being a tropical plant, Water Lettuce thrives most when summer is just starting, with the temperatures still around 60 degrees Fahrenheit (15 Celsius).
For best results, install a partial shade for your Water Lettuce during midday. This protects them against peak mid-day temperatures, especially in hot climates.
Important
Koi pond owners will need to plant Water lettuce in an area inaccessible by their fish as koi like to eat the roots and foliage of this plant.
Water Lettuce Care Guide
It is recommended to prune or trim the flowers and leaves once they start turning brown or yellow. Discarding these leaves and flowers outside of your pond helps to minimize the excess organic material contained in the water.
Water Lettuce does not require fertilization to reproduce – all the required nutrients come from the excess nutrients in the pond water.
Winter Care
Water Lettuce struggles with freezing temperatures or cold water, with the leaves turning white before rotting. So, if you are in Zones 8 and lower, discard your Water Lettuce at the end of the first frost.
Responsible Disposal
Never release water lettuce plants, roots, seeds, rhizomes, or trimmings into lakes, rivers, streams, wetlands, drainage ditches, storm drains, or natural ponds. Do not dump pond or aquarium water containing plant fragments into natural waterways.
Do not compost viable water lettuce if plants or seeds could survive. Dry plants and roots completely, bag them for trash, and never release rosettes or pond water containing fragments into waterways or storm drains.
Water Lettuce Care Card
Download our free printable care card for the Water Lettuce plant! Click the care card below and save the PDF file to your computer. You can easily print off the 3x5 care card or access it right from your phone. Get all the important information you need to keep your Water Lettuce plants healthy and happy!
Plus, we provide a blank card for you to print and fill out yourself. Print it as many times as you like to create cards for all your plants!
Pond Plant Care Card Set
Get the full printable set of 23 pond plant care cards in one PDF. The cards are formatted for quick reference on your phone or easy 3x5 printing.
