From Winter Blues to Blue Larkspur: Growing a Cool-Season Favorite

Late winter can feel long.

The garden is quiet, the beds are unfinished, and spring still feels just out of reach. For me, growing larkspur is a practical way to move forward — a project that bridges winter into spring while there is still cold in the soil and time to prepare. Because my garden itself is still coming together, I’m learning to grow flowers in parallel with building the space they’ll live in.

This is my first season growing larkspur. While the flower is new to me, cool-season growing is not. I have years of experience with snapdragons, foxgloves, and sweet peas — flowers that reward early starts, cool temperatures, and patience. That background shapes how I’m approaching larkspur now.

What follows is how I’m growing it this year, and why.

Larkspur and Delphinium: What to Know

Larkspur (Consolida ajacis) and delphinium (Delphinium elatum) are closely related. Both are known for tall flower spikes and their signature blue tones, though white and pink varieties are also available.

Delphiniums are perennials and have been named the 2026 Flower of the Year. They’re beautiful plants, but they require long-term planning and permanent beds. Because my garden is new and still evolving, I’m not ready to commit fully to perennials yet.

Larkspur, as an annual, offers a way to work with similar forms and colors while keeping flexibility. It allows me to learn how these plants behave in my climate without making long-term decisions before the garden is fully established.

Why I’m Starting in Soil Blocks

Larkspur is most often direct sown, and when beds are ready early, that is usually the simplest approach. Seeds are sown about 1/4 inch deep in cool soil and fully covered, as darkness is required for germination.

This year, however, my beds are still being prepared, and by late February I didn’t want to lose valuable time. To keep the season moving, I’m starting larkspur in soil blocks.

This approach lets me begin while the garden itself catches up.

How I’m Sowing Larkspur

Seeds are pre-chilled for 7 days at 35°F (2°C) to improve germination.

I sow one to two seeds per 3/4 inch soil block, with 200 blocks per stainless steel tray.

Seeds are fully covered, as darkness is required for germination. Rather than covering with soil, I top the tray with another tray to block out all light.

Trays are kept at 65–75°F until germination.

This year germination began in about 7 days, which was faster than expected. However, the overall germination rate was around 50%. Larkspur seeds often benefit from a longer period of cold exposure, so it’s possible the 7-day pre-chill was not long enough to fully satisfy their cold stratification requirement. In future seasons I may experiment with a longer cold treatment to see if that improves germination rates.

After germination the trays are placed under grow lights and the temperature kept no warmer than 55°F.

When seedlings develop one set of true leaves, the soil blocks are nested into larger 2 inch blocks, with 50 blocks per tray.

The seedlings remain in the larger blocks until they are a few inches tall and ready to be hardened off and planted outdoors.

Because this is my first season growing larkspur, I’m treating this as a learning year. Germination rates, timing, and cold treatment length are all variables I’ll continue refining. One advantage of growing annuals is the ability to adjust each season based on what the plants themselves reveal.

Once seedlings are hardened off and outdoor conditions are right — cool soil and workable beds — I transplant carefully to avoid disturbing the roots. My seedlings were here hardened off at 3 weeks old before they had their true leaves. They are doing so well that I am considering planting the 3/4 inch soil blocks directly in the ground instead of bumping them up to larger blocks.

Growing Conditions

Larkspur performs best in cool conditions.

I plant into areas with:

• full sun with some afternoon shade

• good air circulation

• well-draining soil

Seedlings are planted 4–8 inches apart. A horizontal trellis is placed about 2 feet above the ground to support the tall stems. I plan to use a wire fencing trellis supported horizontally with steel fence posts.

Heavy feeding should be avoided. Excess fertility encourages weak growth and shorter stems. Watering is moderate, increasing only during prolonged dry periods.

Harvesting

I harvest larkspur when about one-third of the flowers on a spike are open.

Cutting is done early in the day, and stems go directly into deep, clean water. The remaining flowers continue opening gradually indoors, and stems have a good vase life when handled gently.

Beginning Before Everything Is Finished

Starting larkspur early has given me something tangible to do at a time of year that can otherwise feel stalled. It keeps the season moving, even while the beds are unfinished and spring still feels distant.

If winter has left you restless or impatient for change, growing a cool-season flower like larkspur can be a useful way to regain momentum. It doesn’t require perfect conditions — just cool temperatures, reasonable timing, and a willingness to begin before everything feels ready.