Cactus and semi-cactus dahlias are among the most striking: fully double, uniquely open, varying in size from small to giant.
Their spiky, airy shapes catch less rain and wind, so even big ones often don't need staking.
Cactus dahlia petals are narrow at the base and frequently curve inwards, while semi-cactus dahlia petals are broader at the base and are typically rolled in for part of their length.
Browse the rest of our of dahlias.
Dahlias are wonderfully colourful, vigorous perennial plants with lush leaves and prolific blooms for a generous season.
These tuberous plants can fill the mid-to-late summer flower garden, perhaps with taller shrub roses arrayed behind them, lasting until the first frosts.
Unlike Flower Bulbs, which are mostly very hardy and planted in Autumn, Dahlia Tubers are too tender for planting outdoors in the UK in late Autumn or early Winter.
- Dahlia Tubers are planted when frost has passed and the soil warms up from April-May.
- Many people lift their Dahlias for storage over winter (or get them in the post from us!), pot them up indoors in early Spring, then plant out again in warm soil for a racing start.
- Dahlias are great in good size pots that can still be moved from their outdoor display positions.
For strong establishment and the best flowering, we recommend using Bulb Starter Rootgrow blend.
We sell single-plant tubers, which vary by Dahlia cultivar (type), that's why we hand grade them for you and discard undersize tubers.
- Order now, pay later: we don't charge your card until before delivery
- When your order is ready: your mail order Dahlia tubers are delivered by next working day courier (not the next working day after ordering!)
- Friendly support: if there is anything wrong with your plants when you inspect them, Contact Us within 5 working days
March and April are when early bird gardeners fill pots with Dahlia tubers, either ready to plant out when frost has passed and their soil warms up, or to grow in containers.
In the mildest parts of the South, mid-April is usually frost free and sunny beds should be warm enough for planting out Dahlias.
For most of the UK, wait until May or June bring warmer soils - there is no head start benefit to planting out Dahlias early in cool soil, on the contrary, it sets them back & shortens their season.
Never Bought A Dahlia Tuber Before?
Here's what a tuber looks like and where the "eyes", growth points, are.
- Dahlia tubers are tender, and cold soil will delay their growth.
- Most growers recommended 15C soil temperature to plant outdoors, around May.
- If you are planting them out into the soil directly, but planting is delayed for more than a few days, pot them up temporarily in any old container with only a centimetre of soil/compost covering them, so new shoots immediately have light.
- Taller Dahlia varieties usually need support. We recommend an open centred hoop, which allows the stems to sway naturally without tipping over. Put this in place at planting time, it may be tricky later.
Growing Dahlias
Because they are a tender tuber that can be killed by hard frost, growing Dahlias in borders and growing Dahlias in pots have some special considerations.
Many people lift their tubers to store overwinter, others leave them in the ground and mulch them well.
Lifting allows you to start the tubers early in pots under shelter, then plant them out in late Spring.
Dahlia FAQs
Our premium quality, First Class Dahlia tubers are Dutch, the world leader in Dahlia production.