Dahlias will flower right up until the first frost cuts them down, making them one of the last splashes of colour in an autumn garden.
Dahlias grow from tubers rather than seed and aren’t reliably frost-hardy, so most UK gardeners either lift and store them over winter or take the risk of a deep mulch in milder areas. Regular deadheading and cutting for the house both encourage more flowers rather than fewer.
Sowing & growing calendar
| J | F | M | A | M | J | J | A | S | O | N | D | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Plant | Plant in April | Plant in May | ||||||||||
| Harvest | Harvest in July | Harvest in August | Harvest in September | |||||||||
| Protect | Protect in October | |||||||||||
| Job | Job in July | Job in August |
Care details
- Plant April – May
Plant tubers once frost risk has passed.
- Harvest July – September
Cut flowers for the house — regular cutting encourages more.
- Job July – August
Stake tall varieties and deadhead to keep blooms coming.
- Protect In October
Lift tubers once frost blackens the foliage, or mulch deeply to leave in mild areas.
Growing tips & common problems
- Stake tall varieties at planting time, not once they've grown — inserting a stake later risks damaging the tuber.
- Deadhead and cut for the house often; both encourage the plant to keep producing new blooms.
- Lift and store tubers somewhere frost-free over winter if your garden is cold or waterlogged.
Grows well with
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