Planting Comfrey
Comfrey is a warm season herb 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.
Transplant young plants outdoors 0–2 weeks before your last frost — Comfrey tolerates cool conditions and benefits from an early start.
Spacing and Planting Depth
Give Comfrey room to mature. The figures below come from verified extension and seed-supplier data for typical varieties.
| Spacing in row | 24 inches |
|---|---|
| Row spacing | 36 inches |
| Plants per sq ft | 0.17 |
| Planting depth | 3 inches |
| Sun requirement | Partial sun |
Days to Maturity
Comfrey reaches maturity in 90–120 days from sowing.
Comfrey is ready to harvest after about 105 days. Harvest before the first fall frost, which will end the plant's productive season.
Conditions and Care
As a warm-season herb, Comfrey needs warm soil and settled weather to thrive, and is set back or killed by frost. It is frost hardy and can shrug off light freezes, so it can stay in the ground later into the season than tender crops.
Comfrey grows well in partial sun and tolerates some afternoon shade, which can help slow bolting in warm weather. Sow seed about 3 inches deep, then keep the soil evenly moist until seedlings establish.
Comfrey 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. Comfrey is generally grown as a single planting each season rather than succession sown.
Growing Notes
Perennial; grown from root cuttings as a mulch/compost accumulator.