When to plant and prune Astrantia (masterwort)
Astrantia (masterwort) flowers from late May to early August and the dates below cover planting, flowering and the pruning window.
Planting, flowering and pruning by region
Astrantia (masterwort) 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 mid May | late May to early August | mid February to mid March |
| South Coast and Channel | late March to mid May | late May to early August | mid February to mid March |
| Greater London (Urban Heat Island) | late March to mid May | late May to early August | mid February to mid March |
| South East and Home Counties | late March to mid May | late May to early August | mid February to mid March |
| East Anglia | late March to mid May | late May to early August | mid February to mid March |
| Midlands and Lowland Wales | late March to mid May | late May to early August | mid February to mid March |
| Wales and West Coast | late March to mid May | late May to early August | mid February to mid March |
| Northern England | late March to mid May | late May to early August | mid February to mid March |
| Scotland Lowlands and Central Belt | late March to mid May | late May to early August | mid February to mid March |
| Scotland Highlands and Islands | late March to mid May | late May to early August | mid February to mid March |
| Northern Ireland | late March to mid May | late May to early August | mid February to mid March |
| Channel Islands and Isle of Man | late March to mid May | late May to early August | mid February to mid March |
Growing notes
One of the most reliable perennials for damp partial shade, and very hardy at H7. The papery pincushion flowers last well when cut and dry well too.
At a glance
- Spacing
- 45 cm between plants
- Eventual height
- 75 cm
- Eventual spread
- 45 cm
- Hardiness
- H7
- Sun
- Partial
- Frost tender
- No
- Grows in a container
- Yes, 15 litres or more
- Balcony rating
- 3 out of 5
Feeding
Spring mulch to hold moisture in the soil.
Pruning group
Herbaceous: it dies down in autumn, so cut the old growth to the base in late winter as new shoots appear.
What usually goes wrong
- scorching in hot dry positions
- slugs and snails on young growth
- powdery mildew if the soil dries out
Related guides
Timings cross-checked against RHS guidance for astrantia (masterwort).