Photo: Herman, D.E. et al. 1996. North Dakota tree handbook. USDA NRCS ND State Soil Conservation Committee, Public domain · source
Pruning guide · Broadleaf tree
Box elder: when and how to prune
Acer negundo
Box elder is best pruned in July–October.
| Pruning months | July–October |
|---|---|
| Nesting season (15 March–15 August) | Take care in July–August |
| Flowering | March–April |
| Good for bees, butterflies and birds | Little |
| Native to Belgium | No, naturalised |
Box elder: when to prune it?
In summer or early autumn (July–October). In spring it bleeds heavily.
Bleeds a lot of sap from pruning wounds in late winter and spring. So prune in summer or early autumn, when the tree is in leaf.
What else to prune in those months? July · August · September · October
Box elder: how to prune it?
- On the variegated form, cut out green shoots that ‘revert’ as soon as possible, or they will take over the tree.
- Remove dead, crossing and overcrowded branches; keep the crown open.
- Prune young trees in good time: small wounds heal better than large ones.
How much to cut, and how often?
- One pruning period a year: July–October.
- Never remove more than about a quarter of the crown at once. Better a little every year.
What does it mean for wildlife?
- Pruning in July–August can fall in the nesting season (15 March–15 August). Check carefully for nesting birds first: disturbing an active nest is against the law.
- 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.
- Pruning in late winter or spring: the wounds then bleed heavily.
- Leaving a stub or sawing flush with the trunk: cut just outside the branch collar.
Caution: Don’t prune from late winter into spring: it then bleeds heavily from the wounds.
Nearby: related pruning guides
Similar to: Difference from ash
This guide is compiled from the Bladwijzer plant profile and pruning calendar.