When to plant and prune Wisteria
Wisteria sinensis / floribunda
Skipping the summer prune is the single biggest cause of a wisteria that 'won't flower' — unchecked whippy growth shades out the plant and channels energy into leaves rather than flower buds. Both stages are needed every year; the winter cut alone is not enough. Grafted plants can also take up to 20 years to flower if grown from seed, which is often mistaken for a pruning problem.
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 | early October to late December | early May to late May | mid July to late August |
| South Coast and Channel | early October to late December | early May to late May | mid July to late August |
| Greater London (Urban Heat Island) | early October to late December | early May to late May | mid July to late August |
| South East and Home Counties | early October to late December | early May to late May | mid July to late August |
| East Anglia | early October to late December | early May to late May | mid July to late August |
| Midlands and Lowland Wales | early October to late December | early May to late May | mid July to late August |
| Wales and West Coast | early October to late December | early May to late May | mid July to late August |
| Northern England | early October to late December | early May to late May | mid July to late August |
| Scotland Lowlands and Central Belt | early October to late December | early May to late May | mid July to late August |
| Scotland Highlands and Islands | early October to late December | early May to late May | mid July to late August |
| Northern Ireland | early October to late December | early May to late May | mid July to late August |
| Channel Islands and Isle of Man | early October to late December | early May to late May | mid July to late August |
How to prune it
Two-stage prune: summer (Jul/Aug) shorten whippy growth to 5-6 leaves; winter (Jan/Feb) cut same shoots back to 2-3 buds.
Severity: moderate.
Feeding
Feed in spring with Growmore or Fish, Blood & Bone; add sulphate of potash on sandy soils.
At a glance
- Type
- Climber
- Hardiness
- H5
- Eventual height
- 10.0 m
- Eventual spread
- 10.0 m
- Years to maturity
- 4
- Spacing
- 300 cm
- Sun
- Full sun
- Soil
- Fertile, well-drained soil
- Evergreen
- No
- Fragrance
- Scented
- Pollinator value
- 4 out of 5
- Grows in a container
- Yes, 45 litres or more
- Difficulty
- Hard
Winter protection
Protect open flower trusses with fleece if hard spring frost is forecast, as frost damages and distorts blooms and can cause bud drop.
Safety
All parts, especially seeds and pods, are harmful if eaten.
Growing notes
Buy grafted named cultivars, not seed-raised plants — seedlings can take up to 20 years to flower versus 3-4 years for a grafted plant. Poor long-term container/balcony subject despite being sold as such in garden centres; it wants to be a large wall or pergola plant.
What usually goes wrong
- poor flowering from under-pruning
- spring frost damage to buds
- powdery mildew
- scale insects
- honey fungus
Related guides
Cross-checked against RHS guidance.