Photo: Kurt Stüber [1], CC BY-SA 3.0 · source
Pruning guide · Herbaceous plant
Common duckweed: when and how to prune
Lemna minor
Common duckweed is best pruned in May–September.
| Pruning months | May–September |
|---|---|
| Flowering | June–July |
| Native to Belgium | Yes |
Common duckweed: when to prune it?
From May to September, whenever duckweed covers more than about half of the water surface.
What else to prune in those months? May · June · July · August · September
Common duckweed: how to prune it?
- Skim the duckweed off with a fine-meshed net, a rake or a plank pulled across the water.
- Work from one side: the wind and a plank help to herd the duckweed together.
- Always leave some duckweed behind: it belongs in a living pond.
- Leave the skimmed duckweed on the bank for a day, then put it on the compost heap or use it as mulch.
How much to cut, and how often?
- One pruning period a year: May–September.
What does it mean for wildlife?
- As a native plant, it feeds more insects than a non-native species.
Caution: Don’t let a pond stay completely covered for months: under a closed layer of duckweed, water plants get no light and the water can run short of oxygen.
Nearby: related pruning guides
Plant profile: Common duckweed · Pruning calendar and basic rules
This guide is compiled from the Bladwijzer plant profile and pruning calendar.