Delphiniums are a popular garden plant. They flower in the early summer, bearing their flowers along a tall central spike. Plants can also grow more spikes of flowers lower down the stem. Flower colours range from cream and light pink through red and lilac to deep blue. Delphiniums are famous for being tall plants, grown in the back of the border to give height and structure. There are, however, several shorter varieties available for cultivation.
Tall delphiniums require substantial care. As well as careful watering and feeding, they have to be staked to stay upright, especially in windy situations. Several dwarf varieties have been cultivated that are easier to care for and do not require staking. The Royal Horticultural Society recommends the Magic Fountains Series. These are compact plants that grow to a maximum height of one metre.
Truly miniature delphiniums are uncommon as garden plants. Two that are available to grow from seed are Delphinium tatsienense and Delphinium qinghaiense. These are smaller than dwarf delphiniums. Delphinium tatsienense grows to 30 centimetres, while Delphinium qinghaiense reaches a maximum height of only 10 centimetres. Both originate from the mountain slopes of China.
Care of Miniature Delphiniums
Miniature delphiniums require different cultivation from that for their taller cousins. They are best suited to growing in rock gardens. This situation mimics their natural habitat. They require well-drained, poor soil and should be shaded from strong summer sunlight. An east-facing slope would be ideal. Sow seed in winter and keep moist and covered until germination.
Plant out in late spring after all risk of frost. Dig a hole slightly larger than the root ball of the plant. If the soil is slightly heavy, dig in some coarse horticultural sand or grit to improve drainage. Place the plant in the hole, checking that the surrounding soil is level with the compost in the pot. Fill in the remaining space with soil. Firm gently. Water thoroughly. From then on, be careful not to let the soil dry out but do not over water as this may cause the plant to rot.