Yes. Tropical waterlilies can be overwintered indoors, although successful survival is not guaranteed.
If you want to keep the waterlily actively growing during winter:
- Keep the water temperature above 70°F (21°C).
- Use a thermostatically controlled aquarium heater if needed to maintain a consistent water temperature. Select a heater that is properly sized for the container or aquarium being used.
- Provide a strong full-spectrum grow light for approximately 8–12 hours per day.
- Remove yellow, damaged, or decaying leaves as needed.
- Keep the plant in its aquatic planting container with the crown submerged.
- Avoid strong water movement directly over the plant.
Do I need an aquarium heater?
An aquarium heater can be beneficial when the indoor water temperature may drop below 70°F (21°C).
Maintaining a stable water temperature helps prevent the tropical waterlily from being exposed to repeated temperature swings. If the water naturally remains above 70°F (21°C), an additional heater may not be necessary.
Always follow the aquarium heater manufacturer's instructions for:
- Proper heater size
- Minimum water depth
- Placement
- Temperature setting
- Safe operation
Should I fertilize the waterlily during winter?
If the waterlily continues producing new leaves indoors, aquatic plant fertilizer can be used.
Aquascape Once-A-Year Pond Plant Fertilizer is designed for waterlilies and other aquatic plants. When using the capsule form, push the capsule at least 4 inches (10 cm) into the planting soil.
Do not add additional fertilizer simply because growth appears slower during winter. Lower indoor light levels can naturally reduce growth, and excessive nutrients may contribute to algae.
If the plant stops actively growing, additional fertilizer is generally unnecessary until growth resumes.
Note: Indoor overwintering can help preserve a tropical waterlily, but some plants may still fail to survive. Tropical waterlilies may also produce fewer leaves or flowers indoors than during the outdoor growing season.