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herbPerennial
Comfrey
Symphytum officinale
Also known as: knitbone, Russian comfrey
Vigorous deep-rooted perennial prized as compost activator and mulch plant. Leaves rich in nutrients. Not for internal use.
Growing Requirements
SunFull Sun
WaterMedium
Soil Type
Soil DrainageModerate
Soil pH
Plant Spacing36–48″
Row Spacing36–48″
Planting Depth2–3″
Height24–48″
Spread24–36″
✗ Not Container Friendly✗ Not Raised Bed Friendly
Planting Schedule
Direct Sow (Spring)
2–4 weeks before last frost
Transplant Outdoors
0–9 weeks after last frost
Days to Harvest
60–90 days
Zone Suitability
USDA Hardiness Zones
1
2
3
4
5
6
7
8
9
10
11
12
13
Zones 3–9
Can overwinter in appropriate zones
Perennial in zones 3–9
Plant root cuttings in early spring. Extremely vigorous — nearly impossible to remove. Use Bocking 14 cultivar (sterile, non-spreading).
Companion Plants
No companion data available for this plant yet.