Symphytum officinale - Common comfrey

Description and Uses

Symphytum officinale (Common comfrey) is a temperate plant from North West Europe . It is mainly grown for its multipurpose crops , which have a short shelf life. The crop is harvested by pruning. It starts flowering after 0 - 2 years. The yield will be 0.1 kg/plant DM, but in its top season there will be a yield of 0.5 kg/plant DM. Other crop types include; ornamental, fertilization, repellent pesticide, oil, . The root is used as inedible . The powdered leaf is used as " antidysenteric, " with inulin ({missing data} - {missing data}) as its significant phytochemical. There is comfrey oil extracted by steam distillation from the plant's flower yielding 3% - 4% oil. The plant's wood is called inapplicable and has a density of 100 - 400 kg/m³. Regarding firewood production the plant's growing speed is fast, it's energetic value is 4000 ckal/kg and the wood's drying speed is slow. After 1 years the plant can be totally removed as it reached its commercial and ecological goal. Symphytum officinale has a lifespan of 5 years.

Environmental limitations

The plant is 1 meters tall with a crown of 1 meters wide. The plant prefers a planting distance of 50 cm and a row distance of 100 cm. It is very fast growing and partial shade tolerant. Symphytum officinale has a deep root-system and it has symbiotic associations with the Glomus intraradices fungi (endo-mycorrhiza). It is not able to fix nitrogen with "any bacteria. The name(s) or string of bacteria include(s) "Sinorhizobium americanum ". The plant's flower-morphology is hermaphroditic and is pollinated by bumble bees. Symphytum officinale is deciduous in winter and not allelopathic and has no thorns.

Symphytum officinale thrives in an altitude of 500 to 4000 meters above sea-level (temperate). The minimum temperature is 0°C; optimally between 10 - 25°C. The optimal rainfall is 1650 mm/year. Without irrigation the annual rainfall should be between 900 - 1500mm (L/m²). The optimal soil-pH is between 7.0 - 8.0 in a soil texture of loam. To salt it is a bit tolerant to wind a bit tolerant and to fire intolerant.

Pests and Diseases

Symphytum officinale is susceptible to the following pests: Popillia japonica . And it's susceptible to the following diseases: Smut , , .

Seed Propagation

Seeds are stratificant and can be stored for 8 months. There are approximative 0 seeds/kg. The seeds can be propagated as followed:

• (1) Store harvested seeds moisty at a chilling temperature of 3-7 degrees C for 2-4 months
• (3) press the seeds twice its size in the soil soil.