When to plant and prune Californian Lilac
Californian Lilac flowers from early May to mid June and the dates below cover planting, flowering and the pruning window.
Planting, flowering and pruning by region
Californian Lilac is grown to the calendar rather than to the frost, so the same dates apply across the whole UK and every region below reads the same. Where a plant’s timings do follow the frost, Plot shifts them from the Midlands and Lowland Wales baseline using Met Office average frost dates.
| Where you are | Plant | In flower | Prune |
|---|---|---|---|
| South West Coast and Cornwall | late March to early May | early May to mid June | mid June to mid July |
| South Coast and Channel | late March to early May | early May to mid June | mid June to mid July |
| Greater London (Urban Heat Island) | late March to early May | early May to mid June | mid June to mid July |
| South East and Home Counties | late March to early May | early May to mid June | mid June to mid July |
| East Anglia | late March to early May | early May to mid June | mid June to mid July |
| Midlands and Lowland Wales | late March to early May | early May to mid June | mid June to mid July |
| Wales and West Coast | late March to early May | early May to mid June | mid June to mid July |
| Northern England | late March to early May | early May to mid June | mid June to mid July |
| Scotland Lowlands and Central Belt | late March to early May | early May to mid June | mid June to mid July |
| Scotland Highlands and Islands | late March to early May | early May to mid June | mid June to mid July |
| Northern Ireland | late March to early May | early May to mid June | mid June to mid July |
| Channel Islands and Isle of Man | late March to early May | early May to mid June | mid June to mid July |
Growing notes
Clouds of tiny powder-blue flowers, most spectacular on the evergreen wall-trained kinds in late spring. Short-lived by shrub standards - often 10-15 years - and best treated as a plant to enjoy and then replace. Needs sharp drainage and shelter from cold wind.
At a glance
- Spacing
- 200 cm between plants
- Eventual height
- 250 cm
- Eventual spread
- 250 cm
- Hardiness
- H4
- Sun
- Full
- Frost tender
- No
- Grows in a container
- Yes, 50 litres or more
- Balcony rating
- 2 out of 5
Pruning: what to avoid
Evergreen ceanothus will not reshoot from old bare wood, so never cut back into it - RHS advises replacing an overgrown plant rather than attempting renovation. Deciduous and late-summer types are the opposite: they flower on the current season's growth and are pruned in early to mid-spring.
Pruning group
Evergreen spring and early-summer flowering types: immediately after flowering cut the long flowered shoots back by one third to a half
Winter protection
Mostly hardy in the UK but avoid frost pockets and windy sites; a south-facing wall is the ideal position in colder gardens.
What usually goes wrong
- frost and wind scorch in exposed sites
- brown scale
- root rot in wet soil
- honey fungus
- sudden death of older plants
Related guides
Timings cross-checked against RHS guidance for californian lilac.