🌿 Comfrey

Symphytum officinale

herbs perennial herb

☀️ Sun

full sun to partial shade

💧 Water

moderate to high (prefers consistent moisture)

🗺️ Zones

4–9

🪴 Soil Type

moist, rich loam; tolerates clay

🧪 Soil pH

6.0–7.0

💧 Drainage

moist but well-drained

📏 Spacing

24–36 inches

📐 Height

24–48 inches

📅 Days to Maturity

365 days (perennial, harvest leaves after first year)

🍴 Edible Parts

🍽️ young leaves (cooked🍽️ fritters🍽️ limited consumption due to PAs)🍽️ root (medicinal use only)

🤝 Companions (7)

🤝 Tomato

Comfrey's deep roots mine potassium essential for tomato fruit development; leaf mulch around tomatoes slowly releases nutrients.

🤝 Potato

Comfrey leaves used as mulch in potato trenches provide potassium for tuber formation; decomposing leaves suppress wireworm.

🤝 Apple

Comfrey planted in orchard understory mines nutrients for fruit trees; its dense growth suppresses grass competition around tree bases.

🤝 Asparagus

Comfrey's nutrient-rich leaves used as mulch feed asparagus beds with high potassium needs; doesn't compete with asparagus crowns.

🤝 Gooseberry

Comfrey mulch around gooseberries provides potassium needed for fruit quality; attracts pollinators during gooseberry bloom.

🤝 Bean

Comfrey leaves used as mulch provide potassium and trace minerals that beans need for pod development; beans fix nitrogen comfrey uses.

🤝 Pepper

Comfrey mulch slowly releases potassium and phosphorus needed for pepper fruit development and ripening.

⚠️ Keep Apart (2)

⚠️ Horseradish

Both have deep, aggressive root systems that compete for subsoil nutrients and space; difficult to separate once established.

⚠️ Mint

Mint's aggressive runners invade comfrey's crown; comfrey's dense shade suppresses mint but the root battle creates ongoing conflict.

💊 Medicinal Uses

Cell proliferant (allantoin speeds tissue regeneration). Used externally for bruises, sprains, fractures, wounds, burns, arthritis. Poultice of leaves or root. Contains allantoin (wound healing), rosmarinic acid (anti-inflammatory), mucilage (soothing). Internal use cautioned due to pyrrolizidine alkaloids (PAs) with potential liver toxicity — modern herbalists recommend external use only.

📜 History & Traditional Uses

Known as 'knitbone' in medieval Europe for its ability to speed bone healing. Monastery gardens grew it as essential medicine. Crusaders carried dried comfrey root. First century Greek physician Dioscorides prescribed it. Used in traditional Chinese medicine as 'Comfrey Symphytum'. 19th century Eclectic physicians valued it highly. World War I field medicine used it when supplies were scarce.

📝 Notes

The ultimate permaculture plant — dynamic accumulator with taproots up to 10 feet deep that mine potassium, calcium, magnesium, and phosphorus from subsoil. Use leaves as mulch, compost activator, or make 'comfrey tea' liquid fertilizer. Biomass powerhouse: can be cut 3-5 times per season. 'Bocking 14' cultivar is sterile (non-seeding) and preferred for gardens. Plant where you want it permanently — roots regrow from tiny fragments.