When to plant and prune Hydrangea (Mophead & Lacecap)
Hydrangea macrophylla
Do not prune mophead/lacecap hydrangeas in autumn or winter — leave faded flowerheads on over winter as frost protection for the buds beneath, and only cut back in early/mid spring. Pruning in autumn removes next year's flower buds. This is different from H. paniculata and H. arborescens, which flower on new wood and are hard-pruned every spring.
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 mid November | early July to mid September | early March to late March |
| South Coast and Channel | early October to mid November | early July to mid September | early March to late March |
| Greater London (Urban Heat Island) | early October to mid November | early July to mid September | early March to late March |
| South East and Home Counties | early October to mid November | early July to mid September | early March to late March |
| East Anglia | early October to mid November | early July to mid September | early March to late March |
| Midlands and Lowland Wales | early October to mid November | early July to mid September | early March to late March |
| Wales and West Coast | early October to mid November | early July to mid September | early March to late March |
| Northern England | early October to mid November | early July to mid September | early March to late March |
| Scotland Lowlands and Central Belt | early October to mid November | early July to mid September | early March to late March |
| Scotland Highlands and Islands | early October to mid November | early July to mid September | early March to late March |
| Northern Ireland | early October to mid November | early July to mid September | early March to late March |
| Channel Islands and Isle of Man | early October to mid November | early July to mid September | early March to late March |
How to prune it
Deadhead only; cut faded heads to first strong healthy bud pair in early/mid spring.
Severity: deadhead.
At a glance
- Type
- Shrub
- Hardiness
- H5
- Eventual height
- 1.5 m
- Eventual spread
- 1.5 m
- Years to maturity
- 4
- Spacing
- 120 cm
- Sun
- Partial shade
- Soil
- Moist but well-drained soil, evenly moist; good on clay
- Evergreen
- No
- Pollinator value
- 2 out of 5
- Grows in a container
- Yes, 40 litres or more
- Difficulty
- Easy
Soil pH
Blue flower colour only develops in acid soil (pH 4.5-5); the same cultivars turn pink in alkaline soil. White, red and green cultivars are unaffected by pH.
Winter protection
In cold gardens, leave faded flowerheads on over winter and mulch the base; young growth buds can be damaged by late frosts.
Safety
All parts may cause mild stomach upset if ingested; foliage can aggravate skin allergies — wear gloves.
Growing notes
Feed sparingly — too much fertiliser encourages soft leafy growth prone to frost damage instead of flower buds. Use hydrangea colourant/aluminium sulphate to hold blue in acid soil.
What usually goes wrong
- frost damage to buds
- hydrangea scale
- leaf spot
Related guides
Cross-checked against RHS guidance.