Horticultural Planning Records Est. data · NOAA 1991–2020 · USDA 2023

Herb · Boraginaceae

How to Grow Comfrey

Warm season Frost hardy Partial sun
Days to maturity 90–120
Spacing 24"
Plants / sq ft 0.17
Season Warm

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 row24 inches
Row spacing36 inches
Plants per sq ft0.17
Planting depth3 inches
Sun requirementPartial sun

Plan a square-foot bed with Comfrey →

Calculate plants in a bed for Comfrey →

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.

See Comfrey in the full planting calendar for your ZIP →

Plan crop rotation for Boraginaceae →

Growing Notes

Perennial; grown from root cuttings as a mulch/compost accumulator.

Related Crops

Other crops you might grow alongside or instead of Comfrey.

In the same family

Comfrey is in the Boraginaceae family. Other Boraginaceae crops in the Gardenable database:

Similar growing requirements

Crops with similar season and time to maturity — useful if you want a diverse garden on a similar schedule:

Plan your Comfrey schedule

Comfrey is typically grown as a single planting per season rather than succession sown. Plan your full garden →

Data sources
  • Cornell Extension