Comfrey is a herbaceous perennial plant that can be easily grown and harvested by gardeners for use as a plant food, a compost activator, or a fertilizing mulch. The comfrey leaves are full of rich plant food. Nitrogen, potassium, phosphorous and lots of micro-nutrients become available to other plants as the comfrey leaves decompose. We use comfrey tea as an organic foliar spray.
To harvest the leaves, allow the plant to grow to two feet tall then cut the entire thing to 2″ above the soil surface. The plant will grow back. When it gets two feet tall again, harvest the leaves in the same manner as before. Comfrey leaves can be harvested as many as five or six times throughout the warm growing season but it is important not to take any cuttings after September so the plant has time to rejuvenate itself before winter sets in.
The harvested leaves can be dried in the sun a while and then be spread around the soil as mulch. They can be soaked in water for a couple of weeks resulting in a tea that can be sprayed throughout the garden as a foliar plant food. They can be added directly to the compost pile to jump-start the decomposition process. Some farmers grow comfrey as fodder for chickens and goats.
There are many different types and varieties of comfrey. We grow the ‘Bocking 14‘ cultivar of Russian comfrey. We chose this variety because the seeds are sterile and it does not spread easily through the root system (we didn’t want a variety that would take over all the garden beds but one that would stay contained in its own). Hope this post answers a few questions. :)