Planting Phacelia
Phacelia is a cool season flower in the Boraginaceae 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 Phacelia directly into the garden 0–2 weeks before your last frost.
Spacing and Planting Depth
Give Phacelia room to mature. The figures below come from verified extension and seed-supplier data for typical varieties.
| Spacing in row | 6 inches |
|---|---|
| Row spacing | 8 inches |
| Plants per sq ft | 3 |
| Planting depth | 0.25 inches |
| Sun requirement | Full sun |
Days to Maturity
Phacelia reaches maturity in 45–65 days from sowing.
Phacelia is ready to harvest after about 55 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, Phacelia does its best growing in the cooler weather of spring and fall and tends to bolt or turn bitter in summer heat. It is half-hardy — it withstands light frost but should be protected from a hard freeze.
Phacelia needs full sun — give it at least six hours of direct light a day for the best growth and flavor. Sow seed about 0.25 inches deep — small seed is sown shallow and barely covered, then keep the soil evenly moist until seedlings establish.
Phacelia belongs to the Boraginaceae family; rotating where you grow members of this family each year helps limit the build-up of soil-borne pests and disease. Phacelia is generally grown as a single planting each season rather than succession sown.
Growing Notes
Top pollinator/beneficial-insect cover; also a green manure.