DAZZLING DAHLIAS
These fizzing favourites give colour all the way to autumn
There is no mystery why dahlias are among the world’s best-loved plants. Coming in so many sizes, shapes and colours, there are varieties to suit every taste. They flower constantly between June and November, after which the tubers can be lifted for winter storage, and there are as many as 20,000 varieties, ranging in size from the dwarf to head-high giants.
Most originate from just two wild species — the redflowered Dahlia coccinea and mauve D. pinnata.
Flower shapes vary, too and are classified into 14 groups, including ‘single’, ‘pom pom’, ‘cactus’ and ‘decorative’.
Colours run from white through mauve, pink, lemon or yellow, on to purple, crimson, scarlet and orange. Dahlias can’t be blue, however, because they lack the genes for that.
Containerised dahlias are often on sale at garden centres or flower shows. They will be flowering and ready to plant. But most are sold as dry tubers in late winter or spring.
Plant flowering dahlias now, in fertile soil or in larger containers. Water in with a dilute liquid feed and support tall varieties.
Dahlias swing and in and out of fashion. Thirty years ago, snobby gardeners despised them. But a 1920s variety — Bishop of Llandaff, with its semi-double scarlet flowers and dark bronze foliage, was re-introduced and became an instant hit.
DARK ARTS
ThaT spawned a rash of darkleaved, episcopal dahlias including yellow Bishop of York, purple-red Bishop of Canterbury, orange Bishop of Oxford and lilac Bishop of Leicester.
Other outstanding dark-leaved dahlias include apricot-orange, double-flowered David howard, semi- double, purple- rose Fascination and single, lilacflushed white Twyning’s aftereight. Lower-growing Moonfire has single, broad- petalled flowers in peachy yellow with orange-scarlet centres.
Dark-leaved dahlias go well together. But in a mixed border, light- coloured foliage would create a pleasant contrast with them: silver-leaved wormwoods such as Artemisia ludoviciana or grey-leaved Pearl everlasting, Anaphalis margaritacea would work well.
Choose dahlia varieties with slender stems and medium flowers for containers. To attract bees and butterflies, try singleflowered dahlias such as Moonfire, or peachy happy Single Kiss. Beautiful white Blanc y Verde grows about 90cm but would also be fine in a pot.
SIMPLE CARE
DahLiaS thrive in most soil types. Professional growers apply nitrogen and potash-rich fertilisers. But if your soil is well composted and drains freely, they’ll grow happily anyway.
as the stems grow, the plants will need support from canes and twine or linking stakes.
To keep new buds forming, you must remove all spent flowers. if you haven’t grown dahlias before, those can be mistaken for swelling buds.
Unopened flowers are rounded and plump. Seed heads are more pointed. also, if you gently squeeze a seed head, sap oozes out — unlike with a flower bud.
When cutting dahlias for floral arrangements, choose newly opened blooms gathered in the morning or evening.
after the first frost — or before the end of November — cut the old stems back to about 15cm. Then, either lift the tubers and store them in a frost-free place or leave in the ground. if you do the latter, lay a protective mulch over them for protection.