Photo: AnRo0002, CC0 · source
Pruning guide · Shrub
Bladder senna: when and how to prune
Colutea arborescens
Bladder senna is best pruned in March.
| Pruning months | March |
|---|---|
| Nesting season (15 March–15 August) | Take care in March |
| Flowering | May–August |
| Good for bees, butterflies and birds | Yes, for bees |
| Native to Belgium | No, planted |
| Poisonous to people and pets | Yes, take care with children and pets |
Bladder senna: when to prune it?
In March, before the shrub comes into leaf. It flowers on this year’s shoots, so spring pruning costs no flowers.
What else to prune in those months? March
Bladder senna: how to prune it?
- Cut back last year’s shoots to a few buds above the older wood.
- Remove dead, weak and crossing branches.
- A shrub that has gone bare can be cut back hard, to 30–50 cm above the ground: it usually reshoots well.
- For a smaller shrub, prune firmly every year rather than very hard every few years.
How much to cut, and how often?
- One pruning period a year: March.
- Prune in moderation: never remove more than about a third of the shrub at once.
What does it mean for wildlife?
- Pruning in March can fall in the nesting season (15 March–15 August). Check carefully for nesting birds first: disturbing an active nest is against the law.
- Bladder senna flowers in May–August, when it attracts bees.
- Prunings can go on a dead hedge or brash pile in a corner of the garden: shelter for hedgehogs, wrens and insects.
Common mistakes
- Clipping without first checking for nesting birds.
- Leaving a stub or sawing flush with the trunk: cut just outside the branch collar.
Caution: Do not prune in summer: you would cut off flower buds and pods. Bladder senna is poisonous: wear gloves and keep clippings away from children, pets and livestock.
Nearby: related pruning guides
Plant profile: Bladder senna · Pruning calendar and basic rules
This guide is compiled from the Bladwijzer plant profile and pruning calendar.