The delightful Dwarfhave been developed from the numerous, and somewhat larger, Dahlias grown for exhibition; ‘Jester’ is typical of the group. Dwarf Dahlias may be single- or double-flowered and of most colours and shades – except blue. These half-hardy perennial plants, from the mountains of Central and Southern America, are treated as half-hardy in the UK; like their larger relatives, they develop tubers which can be lifted and dried in the Autumn, then stored cool and dry to be replanted the following year.
The Dwarf Dahlias are excellent for a mass of Summer colour and are compact enough to grow in both tubs and window-boxes; keep them well watered and fed regularly, and the flowers will continue from Summer through to late Autumn.
These frost-tender plants must not be planted out before the end of May. Sow seed indoors from March onwards: it needs 18-21°C (65-70°F) for germination.
Grow Dahlia in good light – a sunny position will result in an excellent display of flowers. Compost around seed, tubers and plants must be kept moist at all times: once the plant is in full growth, water thoroughly and again once the surface of thebegins to dry.
These plants have no need of any additional humidity. On cool and overcast days, don’t over-moisten the crown of the plant: the closely-packed stems may create a close and moist environment where fungal disease will thrive.
Feed from six weeks after planting, using a proprietary plant food: plants grown directly in the ground should not need feeding if thehas been prepared well. Don’t over-feed with nitro-gen. As the plant will produce lots of leaf and few flowers
Grow in a good, free-draining, loam-based compost. Use a peat- based compost for seed and sow about 0.15cm (1/16in) deep. Store over-wintered tubers in dry peat and start into growth in moist peat from March onwards. In Spring, tubers will sprout and produce several shoots: pot the tubers first, allow them to settle into growth once more, then thin the emerging shoots to 2-3 stems.
Pests Dahlias suffer from all the pests that attack succulent bedding plants: Aphids are the most common, but Leaf Hoppers, Red Spider Mite and Thrips are also threats. Treat affected plants as soon as possible with a suitable insecticide.
Diseases: Dahlias grown from tubers are prone to many viruses: destroy infected plants.