When to plant
Plant root divisions in early spring or fall. Grows vigorously all season. Perennial and very long-lived (decades). Dies back in winter, re-emerges in spring. First-year plants should be allowed to establish; full productivity in year 2 and beyond.
Soil & site
Adapts to most soils including poor, clay, or rocky ground. Deep taproot mines nutrients from subsoil. pH 5.5–7.0. Extremely drought-tolerant once established. Plant where you want it permanently — the deep taproot makes it very difficult to move.
Feeding
Does not need external fertilizing — the deep tap root mines its own nutrients. In fact, comfrey IS used to make fertilizer for other plants. Its leaves are high in potassium, phosphorus, nitrogen, and calcium.
Common problems
Virtually no pest or disease problems. Can spread from root fragments — plant the sterile 'Bocking 14' cultivar to prevent unwanted spreading. Very difficult to eradicate once established — every root fragment can regrow. Choose location carefully.
When to harvest
Leaves are ready for harvest when they reach 12–18 inches long — usually 2–3 months after planting. The plant can be cut down 2–4 times per season. For making liquid fertilizer (comfrey tea), harvest the large, mature lower leaves. Use when the plant is actively growing and before flowering.
How to harvest
Cut the entire above-ground growth with a sickle or hedge trimmer 2–4 inches above the crown, or snip individual large leaves. The plant will regrow vigorously. Do not harvest in the first year from root divisions — let it establish. In subsequent years, cut 3–4 times per season. Use immediately as mulch, chop-and-drop, or make into liquid fertilizer.
Storage & use
Fresh leaves used as mulch, green compost activator, or chop-and-drop fertilizer for fruit trees. For comfrey tea: pack leaves into a container, weigh down, add water, and let ferment for 4–6 weeks (it smells terrible). Dilute 1:15 for a powerful liquid fertilizer. Avoid internal consumption — contains alkaloids.
Useful for growing comfrey
A few things that make this one easier — chosen for this plant, not a generic list.
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