Photo: Ivar Leidus, CC BY-SA 3.0 · source
Pruning guide · Perennial
Greater knapweed: when and how to prune
Centaurea scabiosa
Greater knapweed is best pruned in March.
| Pruning months | March |
|---|---|
| Flowering | June–September |
| Good for bees, butterflies and birds | Yes, for bees, butterflies and birds |
| Native to Belgium | Yes |
Greater knapweed: when to prune it?
From late February to late March, before the new rosettes start into growth.
What else to prune in those months? March
Greater knapweed: how to prune it?
- Leave the spent stems and seed heads standing all winter.
- In March, cut the old stems back to just above the rosette of leaves.
- If you want fewer seedlings, cut off some of the seed heads once the birds have finished with them.
How much to cut, and how often?
- One pruning period a year: March.
What does it mean for wildlife?
- Greater knapweed flowers in June–September, when it attracts bees and butterflies.
- If you only cut back in March, the old stems stand through the winter: insects overwinter in them and birds eat the seeds.
- As a native plant, it feeds more insects than a non-native species.
Caution: Do not cut back in autumn: that way goldfinches keep their winter food and insects can overwinter in the stems.
Nearby: related pruning guides
Plant profile: Greater knapweed · Pruning calendar and basic rules
This guide is compiled from the Bladwijzer plant profile and pruning calendar.