Delphinium - Key Growing Information
DAYS TO GERMINATION: 10-20 days at 65-70°F (18-21°C)
SOWING: Transplant (recommended) - Sow 10-16 weeks before last frost. Support strongly advised. Cover seed lightly. Transplant into larger cell packs or 3-4" containers 6-8 weeks after germination. Grow seedlings at 50-55°F (18-21°C) in the greenhouse or cold frames. Harden off and transplant outside after the last frost. Overhead irrigation is not advised. If growing in the greenhouse, transplant plugs into raised bed in August through September. Provide Hortonova (horizontal trellis) 12-18" above the beds. Keep temperatures below 60°F (16°C), in a heated structure. Feed with a balanced fertilizer. Direct seeding is not recommended.
LIGHT PREFERENCE: Sun/Part Shade.
PLANT HEIGHT: Varies. Providing support is strongly advised.
PLANT SPACING: 12-18" if being grown as a perennial. 12" apart if being grown as an annual.
HARDINESS ZONES: Zones 3-7 A short-lived perennial, generally only lasting 3 seasons.
HARVEST: 1/4 to 1/3 of flowers on stem are open. Place immediately in water.
Plants boom again in late summer and early fall if cut back immediately after the first bloom.
SOIL REQUIREMENTS: Well-drained, fertile, slightly alkaline soil with plenty of organic matter. Fertilize lightly but frequently with a balanced fertilizer.
USES: Excellent cut flower. Well suited to perennial beds and borders.
SCIENTIFIC NAME: Delphinium spp.
ALTERNATE NAME:Candle larkspur