Water lettuce
Pistia stratiotes · Araceae
The gardener's calendar
Ideal time to plant water lettuce: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Common name
- Water Lettuce
- Family
- Araceae
- Type
- Floating aquatic plant
- Adult size
- 10 to 15 cm in diameter
- Foliage
- Evergreen
- Growth
- Very fast
- Hardiness
- Frost-tender (tropical and subtropical climates)
- Origin
- Tropical Africa
Care
Light Exposure
Water lettuce thrives in full light, requiring at least 6 hours of direct sun daily. It tolerates partial shade but grows less vigorously in such conditions. Place it in a well-lit area of your pond or aquarium for best results.
Water Conditions
Maintain water temperature between 20 and 28 °C for optimal growth. The water should be soft to moderately fertile. Change part of the water regularly to prevent waste accumulation and maintain good ecological balance.
Nutrition
Supplement with liquid fertilizers specific to aquatic plants once or twice monthly, especially during the growing season. You can also use nutrient tablets placed in the pond substrate if present. Avoid excess fertilization, which promotes unwanted algae.
Maintenance and Propagation
Remove dead or damaged leaves regularly to keep the plant in good condition. Water lettuce naturally multiplies by producing daughter plantlets connected by runners. Divide and thin out the colony if it becomes invasive.
Substrate (if pond has soil)
If your pond contains a substrate, prefer nutrient-rich soil to anchor the floating roots. A mixture of fertile silt and fine gravel provides good support. Ensure the substrate doesn't impede water circulation.
Common Issues
Leaf rot can occur with stagnant water or temperatures that are too low. Inspect the plant regularly and remove affected parts. Aphids and other aquatic pests are possible in closed aquariums: isolate the plant if needed and rebalance the ecosystem.
Did you know?
Water lettuce is considered a major invasive species in many tropical and subtropical ecosystems, capable of forming floating mats so dense they block light and oxygen. Despite this, it has been cultivated since ancient times in Egypt and South Asia for decoration and natural water purification. Its accidental global spread illustrates the challenges of managing ornamental aquatic plants.
Where to buy it
Best planted in spring or autumn, away from frost and heatwaves. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September, October.
Add this plant to my garden →Plants from the same family
- Calla lilyZantedeschia aethiopica
- TaroColocasia esculenta
- Giant taroAlocasia macrorrhizos
- Tree PhilodendronThaumatophyllum bipinnatifidum
- ZZ plantZamioculcas zamiifolia
- Anthurium albumAnthurium album
Tips generated and checked by Viridia — adapt them to your local climate.