Comfrey, 'Bocking 14'

Symphytum × uplandicum 'Bocking 14'

A true garden workhorse, Bocking 14 Comfrey is a vigorous perennial prized for its large, nutrient-rich leaves and usefulness in regenerative gardening. Its broad, dark green foliage and clusters of purple-blue, bell-shaped flowers make it a substantial addition to the garden, while its flowers provide nectar for pollinators. 

Comfrey is particularly valued in permaculture and organic gardening systems. Its deep root system accesses nutrients from below the surface, and its abundant foliage can be harvested for compost, used as a nutrient-rich mulch, or steeped in water to make a homemade liquid plant feed. Bocking 14 is a sterile Russian comfrey cultivar, meaning it does not produce viable seed, unlike its cousin, common comfrey. However, small pieces of root can regenerate, so choose its planting location carefully.

Location: Pretty and interesting enough to be placed in both ornamental beds and veggie gardens, and will attract pollinators. We see a great many bumblebees throughout the year going crazy for comfrey flowers.

Height: 3-4 feet, with flowering spikes potentially taller, Spread: 2-3 feet, although established clumps spread slowly over time.

Light: Can tolorate full sun, but does best with later day shade in the hottest months, especially in Texas. 

Soil: Adaptable to clay, loam, and sandy soils, but does best in fertile soil with high organic matter. 

Water: Moderate. Keep the soil consistently moist while plants establish. Mature plants tolerate some drought, but reliable moisture encourages more abundant foliage and regrowth after harvesting. Foliage may die back to the ground if not watered in the summer, but will come back from its large taproot.

Heat Tolerance: Good. Comfrey grows vigorously in warm weather but may wilt or slow down during prolonged extreme heat, particularly in dry soil. Afternoon shade and adequate moisture can help in Texas. .

Cold Tolerance: Good. Bocking 14 is a hardy perennial variety that dies back to the ground or becomes dormant during winter and regrows from its established root system in spring. Even temperatures in the low teens are unlikely to cause the root mass harm due to the depth of the taproot. Mulching the crowns with a thick layer of wood chips or straw would be advisable when temps drop to below 20.

USDA Hardiness Zones: Generally Zones 4–9.

Propogation: Bocking 14 is propagated through root cuttings or division rather than seed. Even small root fragments can produce new plants, so avoid cultivating the soil around unwanted root pieces if you need to contain it. It will only spread very very slowly if left undisturbed.

Harvest and Use: Once established, harvest the leaves several times during the growing season, cutting the foliage back while leaving the crown and growing points intact. Use the leaves as compost material, mulch around established plants, or as an ingredient in homemade liquid plant feed. Allow the plant time to regrow between harvests, but there is no limit to the number of times per year the leaves can be harvested.

Important Note: Comfrey contains pyrrolizidine alkaloids associated with liver toxicity when ingested. It should not be promoted for eating or making consumable teas. Its strongest uses are as a biomass crop, mulch, compost activator, and in salves.