Photo: Nikanos, CC BY-SA 2.5 · source
Pruning guide · Broadleaf tree
Grey alder: when and how to prune
Alnus incana
Grey alder is best pruned in November–March.
| Pruning months | November–March |
|---|---|
| Nesting season (15 March–15 August) | Take care in March |
| Flowering | February–March |
| Native to Belgium | No, naturalised |
Grey alder: when to prune it?
During winter dormancy (November–March).
Prune while dormant, from November to March, but not in freezing weather.
What else to prune in those months? January · February · March · November · December
Grey alder: how to prune it?
- Regrows readily after cutting back: manage it as coppice or in a hedgerow and cut it down low every few years.
- A free-standing tree needs little pruning: just remove dead, broken and crossing branches.
- Mow or cut off root suckers.
How much to cut, and how often?
- One pruning period a year: November–March.
- Can be cut back to just above the ground every few years and will then regrow.
- 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 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.
- 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: Don’t coppice in hard frost, and cut at a slant so that rainwater runs off the stool.
Nearby: related pruning guides
Similar to: Difference from alder · Difference from hornbeam
Plant profile: Grey alder · Pruning calendar and basic rules
This guide is compiled from the Bladwijzer plant profile and pruning calendar.