Delphinium: Sowing, planting and harvest calendar
When and how should you sow delphiniums outdoors?
Before sowing delphiniums outdoors, check the group named on the packet. Annual larkspurs and perennial delphiniums do not all follow the same calendar. Choose a period that matches their germination requirements and your climate, when the soil is no longer waterlogged. A late sowing of a perennial may not flower until the following year, so do not expect immediate blooms.
Prepare a fine surface free of competing weeds, in soil that drains well while retaining some moisture. Sow thinly and cover only to the depth specified for your chosen type, rather than burying every seed 1 cm deep. Firm gently and water with a fine spray. Mark the row with a label so you can recognise emerging seedlings and avoid removing them while weeding.
Keep the seedbed moist without soaking it and watch for slugs that may eat young seedlings. Once true leaves develop, thin according to the variety's mature spread; 30 cm does not suit every tall hybrid. Annual larkspurs are often sown directly where they will grow. For a perennial with particular requirements, controlled sowing in a container may be easier than direct sowing.
When and how should you plant a delphinium?
When do delphiniums bloom and how should you care for their flowers?
