Now is about the time that I start my unpromising, wrinkly brown dahlia tubers off in large black plastic pots in the polytunnel. I use multipurpose compost to just cover the tubers and then keep them moist until shoots start appearing. They can then be planted out after the frosts are over - usually towards the end of April or beginning of May. The tubers can also be planted directly in the ground once the danger of frosts is past.
Dahlias have been unpopular in the past, conjuring images of pompom blooms of red, sherbet lemon or candy floss pink standing to attention in uniform rows, often next to the veg plot. However, dahlias can be used successfully alongside other perennials, flowering from July until November. The bonus is that they produce an abundance of cut flowers which go on producing, the more the blooms are cut.
Dahlias are classified according to their flower shape into 13 groups: singles, anemone-flowered, collarette, waterlily, decorative, ball, pompon, cactus, semi-cactus, miscellaneous, fimbriated, single and double orchid. Suffice it to say that there are dahlias of all shapes and sizes to suit all tastes!
Here are some of my favourites from summer 2014:-
Dahlia 'Clair de Lune' is an exquisite pale yellow, collarette type - the Audrey Hepburn of the dahlia world.
Dahlia 'Blue Bayou' is an anemone-flowered dahlia of lilac pink.
Dahlia 'Happy Single First Love' is a beautiful peach with a central red ring and contrasting dark foliage. Not too tall at 60cm and bees love the single flowers.
Dahlia 'Downham Royal' is a ball type of deep pinkish red.
Dahlia 'Autumn Lustre' is a decorative type of rich orange.
Dahlia 'Jescot Julie' is a double orchid type with petals that are marmalade orange on top and plum on their undersides. It mixes well with deep reddish black dahlias such as 'Chat Noir' and 'Rip City'
Dahlia 'Waltzing Matilda' is a short, single type dahlia with dark foliage and contrasting flowers of sunset orange with a red flush.
Dahlia 'Happy Halloween' is a perfectly formed decorative dahlia of deep pumpkin orange.
The following photos were taken at Ulting Wick in Essex, a garden open under the National Gardens Scheme which boasts a large display of dahlias skilfully combined with late summer annuals and perennials.
Cactus type Dahlia 'Ludwig Helfert' with Verbena bonariensis
Decorative type dahlia 'Orange Cushion' with the annual Amaranthus 'Hopi Red'
The deep reddish purple decorative type dahlia 'Admiral Rawlings' with Miscanthus 'Pink Flamingo. This dahlia is very tall so definitely needs staking and possibly not a choice for the small garden.
A stunning cactus type Dahlia 'Pontiac' with pink spiky flowers.
Semi-cactus type Dahlia 'Park Princess' with the flowing grass Pennisetum orientale
Dahlias will need staking during the growing season and can be cut down to the ground once their foliage turns black with the frost in November. They can then be lifted (if your soil is wet during winter) or left in the ground if your soil is free-draining.