Dwarf Larkspur Summer Blues Seeds - Delphinium grandiflorum

Sow the seeds of Delphinium Summer Blues directly outdoors, from April to May, in full sun, in a fertile, light, well-drained soil that has been previously prepared. Bury the fine seeds to a depth of 6mm (0.2 in) in small holes spaced 30cm (11.8 in) apart. Keep the soil moist by watering regularly, especially during dry periods. Germination usually takes 14 to 21 days. When the seedlings are large enough to handle, thin them out by planting only one plant every 15cm (5.9 in).

For earlier flowering, sow Delphinium seeds from August to October in 7.5cm (2.8 in) pots filled with good quality compost kept moist. Place the pots in a mini-greenhouse or inside a plastic bag at a temperature of 15-20°C until germination. Once the seedlings have developed, place them in a bright, but cooler location. Overwinter the plants in a cool, bright place protected from frost by watering them sparingly. Transplant them to their final location in the following spring. Water regularly until the plants are fully established.

Regularly remove faded flowers to encourage continuous flowering. Delphiniums prefer sunny locations protected from the wind, as well as a fertile soil rich in organic matter and well-drained. Excessively wet or dry soil is detrimental to the growth and flowering duration of the larkspur. Varieties derived from Delphinium grandiflorum are more resistant to diseases and pests than the large hybrids. They also tolerate heat better.