Rocket Larkspur Imperial Mix Seeds

Skip the indoor start, as Imperial Mix Rocket Larkspur has a taproot that does not survive transplanting. Sow Delphinium Consolida seeds directly in the garden in early spring, as soon as the ground is workable, when soil temperature is between 50–65°F (10–18°C). You can also sow Larkspur Rocket seeds in fall. For that broadcast the seeds in late autumn, let them stratify over winter naturally, and they will sprout on their own schedule in early spring. Sow ¼ inch deep, press lightly, and keep the surface moist. Under the right conditions Delphinium Consolida seeds germinate in 14–21 days.

Rocket Larkspur needs full sun — at least 6 hours a day. In partial shade, the stems get leggy and fall over before they even flower. They can grow in basically any well-drained soil, but give them deep, loose, compost-enriched ground with a near-neutral pH (6.0–7.0) and you will get taller stems and more blooms. Water consistently during germination, early growth and during blooming. In warmer zones, add a thin layer of mulch around the base to retain moisture and prolong blooming for a  few extra weeks.

Thin Larkspur Rocket seedlings to 6–12 inches apart when they hit 2–3 inches. In exposed spots or windy gardens, stake plants at early stages. To keep flowering going as long as possible, deadhead spent spikes regularly. If you want the plant to self-sow and come back next year on its own, leave a few seed heads to mature on the plant. For cut flowers, harvest stems when the bottom third flowers are open and the rest is still in tight bud. Plant lasts 7–10 days in vase.