Planting Larkspur
Larkspur is a cool season flower in the Ranunculaceae family. Getting the timing right is the difference between a strong stand and a disappointing one, so the windows below are given relative to your own last spring frost and first fall frost rather than a generic calendar date. Look up your local frost dates and count back or forward from there.
You can sow Larkspur directly into the garden 2–4 weeks before your last frost.
Spacing and Planting Depth
Give Larkspur room to mature. The figures below come from verified extension and seed-supplier data for typical varieties.
| Spacing in row | 9 inches |
|---|---|
| Row spacing | 12 inches |
| Plants per sq ft | 1.33 |
| Planting depth | 0.125 inches |
| Sun requirement | Full sun |
Days to Maturity
Larkspur reaches maturity in 85–110 days from sowing.
Larkspur is ready to harvest after about 98 days. Harvest before summer heat or, for fall crops, before a hard freeze, to keep quality high.
Conditions and Care
As a cool-season flower, Larkspur does its best growing in the cooler weather of spring and fall and tends to bolt or turn bitter in summer heat. It is frost hardy and can shrug off light freezes, so it can stay in the ground later into the season than tender crops.
Larkspur needs full sun — give it at least six hours of direct light a day for the best growth and flavor. Sow seed about 0.125 inches deep — small seed is sown shallow and barely covered, then keep the soil evenly moist until seedlings establish.
Larkspur belongs to the Ranunculaceae family; rotating where you grow members of this family each year helps limit the build-up of soil-borne pests and disease. Larkspur is generally grown as a single planting each season rather than succession sown.
Growing Notes
Cool-season cut flower; needs cold to germinate. Toxic if eaten.