In the fall, remove yellowing or dead aquatic plant growth before it decomposes in the pond. How far you trim depends on the type of plant.
- Hardy marginal plants: Trim dead or yellowing foliage to about 2–4 inches (5–10 cm) above the water or plant crown. Do not cut into the crown.
- Hardy water lilies: Cut yellowing leaves and flower stems to about 1–2 inches (2.5–5 cm) above the crown.
- Lotus: Allow foliage to yellow naturally, then cut the stems several inches above the waterline. Do not cut hollow stems below the water.
- Floating tropical plants: Remove plants such as water hyacinth and water lettuce before freezing temperatures.
- Tropical lilies and marginal plants: Move them indoors before freezing temperatures if you plan to overwinter them.
Do not cut healthy green foliage simply because fall has arrived. Wait until the plant begins to naturally die back.