Humans have been growing comfrey as a healing herb for more than 2000 years, as I myself have (for slightly less than 2000 years though!). Comfrey is still used in external preparations to heal wounds. And is perfect grown as a green manure or animal feed crop.
Comfrey is usually propagated by root cuttings or crown pieces, or buy small plants from a garden centre or your preferred online supplier. But you can start it from seed. For UK deliveries this link will take you to the comfrey seed page at Thompson & Morgan (UK).
Comfrey is a deep-rooted plant and will not do particularly well in shallow soil. It prefers a fertile soil, as do most plants, but is a hardy perennial and will propagate year after year if situated well. Position in a sunny spot, although full sun is not essential.
Start your comfrey patch with small plants, root cuttings or pieces of the crown of an established plant. If you’re starting with seeds, grow them in pots until ready to plant out.
Plant root cuttings 2-4 inches (5-10cms) deep depending on the size of the cutting, laying the root cutting flat in the dug hole. Water well and let it grow!
Growing comfrey in your garden should be planned well, as it will grow bigger every year.
One of the major practical uses for the average gardener is growing comfrey as a green manure. You can simply lay the harvested leaves on the ground around your vegetables as a mulch or you can go all out and make your very own organic tonic.
I used this fertilizing method for a number of years and had great results, so grew comfrey all over the place.
Growing Comfrey – making a Tonic for your veggies:
If you have enough space, growing comfrey will provide a tonic for your vegetable patch. The tonic allows the plants to extract more nutrients from the soil.
First you need a container, preferably the size of a small dustbin, with a tap near the bottom. A small filter should also be used to avoid clogging the system. It must have a lid, and you will need a weighty object such as a large flattish stone, almost the size of the radius of your container. Raise your container off the ground, leaving enough room to comfortably place a watering can under the tap.
Collect as much comfrey as you can and pack it into the container, on top of the filter. Add a wire mesh or something similar and place your heavy object on top to hold the leaves down, then cover them with water. Put the lid on and forget about it for a couple of weeks.
When you’re ready to feed your plants, first put a peg on your nose, or don’t breathe in too hard, ( it really hums! ) and collect from the tap about a litre of the green slimy liquid into your watering can.
Top up the can with fresh water and feed your veggies. An exact ratio of tonic to water isn’t necessary but don’t put it on the ground undiluted. It’s too strong for most small plants.
Try and use all the available tonic in one go, clear out the slush ( put it directly on the compost heap) then make some more. Comfrey can be easily cut three or four times a year, but if you find a shortage occurring, try adding a few nettles to your mix.
Growing comfrey in your garden provides an organic food for your vegetable patch without costing a bean!
Please note There have been recent tests done on rats using Symphytine (a constituent of comfrey) that have shown carcinogenic results. However, these results aren’t really conclusive as the tests use highly concentrated forms of Symphytine.