When to plant and prune Buddleja (Butterfly Bush)
Buddleja davidii
Prune hard every year in early spring (late March-mid April), not in autumn — B. davidii flowers on the current season's growth, so a hard spring cut boosts (not costs) that summer's flowers. Leaving old stems unpruned produces a taller, straggly shrub with smaller flower panicles.
Planting, flowering and pruning by region
Pruning is driven by dormancy rather than frost, so it is not shifted by region — the same cut is right in Inverness and in Penzance. Planting windows do move.
| Where you are | Plant | In flower | Prune |
|---|---|---|---|
| South West Coast and Cornwall | late March to mid May | late June to late September | late March to mid April |
| South Coast and Channel | late March to mid May | late June to late September | late March to mid April |
| Greater London (Urban Heat Island) | late March to mid May | late June to late September | late March to mid April |
| South East and Home Counties | late March to mid May | late June to late September | late March to mid April |
| East Anglia | late March to mid May | late June to late September | late March to mid April |
| Midlands and Lowland Wales | late March to mid May | late June to late September | late March to mid April |
| Wales and West Coast | late March to mid May | late June to late September | late March to mid April |
| Northern England | late March to mid May | late June to late September | late March to mid April |
| Scotland Lowlands and Central Belt | late March to mid May | late June to late September | late March to mid April |
| Scotland Highlands and Islands | late March to mid May | late June to late September | late March to mid April |
| Northern Ireland | late March to mid May | late June to late September | late March to mid April |
| Channel Islands and Isle of Man | late March to mid May | late June to late September | late March to mid April |
How to prune it
Hard prune to a low framework each spring.
Severity: hard.
At a glance
- Type
- Shrub
- Hardiness
- H5
- Eventual height
- 2.5 m
- Eventual spread
- 2.5 m
- Years to maturity
- 3
- Spacing
- 150 cm
- Sun
- Full sun
- Soil
- Any well-drained soil, tolerates poor soil
- Evergreen
- No
- Fragrance
- Scented
- Pollinator value
- 5 out of 5
- Grows in a container
- Yes, 40 litres or more
- Difficulty
- Easy
Growing notes
Self-seeds freely and is classed as a non-native naturalised/potentially invasive plant on waste ground — deadhead spent flower spikes to limit self-seeding into the wild.
What usually goes wrong
- aphids
- capsid bug
- root rot in waterlogged winter soil
Related guides
Cross-checked against RHS guidance.