From my perspective as a Delphinium, successful growth begins with a period of cold stratification. In my native habitat, I naturally disperse my seeds in late summer or fall, and they overwinter in the cold soil. This chilly, moist period breaks my seed coat's dormancy, signaling that it's safe to germinate after the danger of a hard frost has passed. To replicate this, you should place my seeds in a moist seed-starting mix within a sealed plastic bag and refrigerate them for about one to two weeks. This mimics the winter cold I instinctively require.
I am quite particular about my bed. I require a light, well-draining, and sterile seed-starting mix. Heavy garden soil is unacceptable as it can harbor fungi that will attack my delicate seedlings (a condition you call "damping-off"). Sow my seeds on the surface of the moistened mix, as I need exposure to light to trigger germination. Gently press them into the soil for good contact, but do not bury me deeply. A dusting of vermiculite is acceptable as it retains moisture while allowing light to penetrate.
Once sown, I need consistent moisture and the right temperature to sprout. Keep the soil consistently moist but not waterlogged. The ideal temperature for my germination is around 65-75°F (18-24°C) during the day, with a slight drop at night. Place my container in a bright location, but out of direct, scorching sunlight. Under these conditions, I should begin to emerge within 14-21 days. As a seedling, I am tender and vulnerable. Handle me only by my first leaves (cotyledons) if you must transplant me, and be very gentle with my roots.
I cannot go directly from the protected indoors to the harsh outdoor garden. The sun would scorch my leaves, and the wind could break my stem. I need a gradual transition, a process you call "hardening off." Over 7-10 days, please gradually expose me to outdoor conditions. Start with a sheltered, shady spot for just an hour or two, slowly increasing the time and introducing me to morning sun. After this acclimatization period, I am ready for my permanent home. Choose a location with full sun to light afternoon shade and rich, well-draining soil.
To grow into the majestic, towering spires I am destined to be, I require specific ongoing care. My roots are shallow yet hungry. I need consistently moist soil, especially during hot, dry periods; a layer of mulch helps immensely with this. I am a heavy feeder and will reward you with vigorous growth and spectacular blooms if you provide a balanced, slow-release fertilizer at planting time and again as I begin my rapid growth in spring. Given my height, I insist on sturdy staking or support to prevent my flower-laden stalks from toppling over in a summer storm.
