How to Prune yellow floating heart?
Deadhead and remove yellow leaves regularly

yellow floating heart · Nymphoides peltata
Also known as: dwarf waterlily; fringe; fringed buckbean; fringed water lily; small yellow water lily; water fringe
This plant is listed on Schedule 9 of the UK Wildlife & Countryside Act as an invasive non-native species. Although not banned from sale, it is an offence to plant or cause these to grow in the wild in NORTHERN IRELAND and the REPUBLIC OF IRELAND. Gardeners possessing them should undertake measures to control them. See RHS advice on invasive non-native species for further information
Deadhead and remove yellow leaves regularly