Dahila Tubers - A Quick Guide
Native to Mexico, it's no surprise that dahlias like a sunny spot. Give them fertile, free-draining soil and you'll have happy tubers. Dahlias vary widely in their flower shapes and colours and offer huge interest for any gardener growing them.
Popular with Victorians, growing somewhat out of fashion in the latter part of the 20th century, dahlia tubers are back with a botanical bang and seen everywhere from the RHS Chelsea Flower Show (where they are forced to flower early) to the RHS shows at Hampton Court and Tatton Park where, in 2019, borders full of dazzling dahlias were on hand to welcome visitors.
What is the difference between dahlia bulbs and tubers?
Although often referred to as dahlia bulbs, dahlias are actually tubers. Visually a bulb looks like an onion and a tuber looks like a potato. A bulb, like an onion, has lots of layers formed from modified leaves with a compact stem and roots at the base. A tuber is a modified stem that stores nutrients, with buds that sprout and shoot upwards from multiple places.
More compact varieties are used for bedding plants, but the ones that really take your breath away are the taller specimens with large blooms, bound to impress.
The dahlia on every high-end horticulturalist's list is 'Cafe au Lait' - a true beauty - a creamy coffee colour - it is much prized as a cut flower and very respected in the industry. Sophisticated and stately, one not to miss.
Cactus dahlias are very popular for their quirky shaped blooms - 'Park Princess' is a perfect example, befitting of its royal name and a reliable purchase from royal warrant holders, Suttons!
Pompom types look neat, their spherical blooms perfect for picking. 'Golden Scepter' will brighten any border.
When to plant dahlia tubers
- For early flowering, start tubers in pots of compost during March and April, keep in a greenhouse or windowsill.
- Harden off, ready for planting outdoors in late May / early June when the danger of frost has passed.
- Alternatively, plant directly outdoors during May, with the top of the tubers about 7.5cm (3") deep and 50-90cm (2.5-3') apart
- Be prepared to give protection against frost.
- In autumn lift, dry and store the tubers for winter, in dry peat, or sand, in a cool frost free place.
Read our Best Expert Advice on Growing Dahlias for more information.