When to plant and prune Tuberous begonia
Tuberous begonia flowers from mid June to late September and the dates below cover planting, flowering and the pruning window.
Planting, flowering and pruning by region
Tuberous begonia is frost-tender, so its timings shift across the UK. Plot works them out 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 | mid April to early May | mid June to late September | mid June to late September |
| South Coast and Channel | late April to mid May | mid June to late September | mid June to late September |
| Greater London (Urban Heat Island) | mid April to early May | mid June to late September | mid June to late September |
| South East and Home Counties | early May to late May | mid June to late September | mid June to late September |
| East Anglia | mid May to early June | mid June to late September | mid June to late September |
| Midlands and Lowland Wales | late May to mid June | mid June to late September | mid June to late September |
| Wales and West Coast | early May to late May | mid June to late September | mid June to late September |
| Northern England | late May to mid June | mid June to late September | mid June to late September |
| Scotland Lowlands and Central Belt | early June to late June | mid June to late September | mid June to late September |
| Scotland Highlands and Islands | late June to mid July | mid June to late September | mid June to late September |
| Northern Ireland | mid May to early June | mid June to late September | mid June to late September |
| Channel Islands and Isle of Man | mid April to early May | mid June to late September | mid June to late September |
Growing notes
Depth: this is the exception to the two-to-three-times rule - start tubers just 2.5cm deep, hollow (concave) side upwards, in March or April at about 18C, then plant out only after the danger of frost has passed. Thrives in partial shade and flowers non-stop until the first frosts; the big double flowers are shredded by wind and scorch in full midday sun. Double-flowered bedding begonias offer almost nothing to pollinators.
At a glance
- Spacing
- 45 cm between plants
- Eventual height
- 35 cm
- Eventual spread
- 35 cm
- Hardiness
- H3
- Sun
- Partial
- Frost tender
- Yes
- Grows in a container
- Yes, 10 litres or more
- Balcony rating
- 5 out of 5
Feeding
Weekly high-potassium liquid feed from when plants are growing strongly until September.
Pruning group
Deadhead spent flowers regularly to keep plants flowering until the first frosts
Winter protection
Tender. Lift tubers before the first frosts: reduce watering as the leaves yellow, then store the dry tubers in barely moist soil or sand in a frost-free shed at around 7C over winter.
What usually goes wrong
- tuber rot in wet soil or in storage
- powdery mildew
- leaf spot
- damping off of young shoots
- foliage scorch in hot sun
Related guides
Timings cross-checked against RHS guidance for tuberous begonia.