Comfrey is a vigorous, fast growing plant. Comfrey grows easily from root cuttings. If you know anyone who has a comfrey plant, you can easily get a root cutting from them. I had a plant in our flower bed. I very soon had many comfrey plants in our flower bed. We dug them out and divided them and planted them around the farm. (They are good for chickens and cattle.) But I still have comfrey in our flower bed. It is almost hard to get rid of, so consider this as a bit of a warning. Plant it where you want it for several years. It can last for several decades. Each piece of root will produce a plant.
It grows best in fertile soil with plenty of moisture. But its roots are deep and it can survive and grow in dry, less fertile soil also. It is not particular as the the ph of the soil. It prefers sun but will grow in shade.
There are several ways to use is as a garden fertilizer. The leaves can be harvested whenever they are tall enough, about 15-18 inches. Cut them off about 2 inches above the soil. You can bury a leaf under your tomato and pepper transplants. Be sure there is a little soil on top of the comfrey leaf before you put in the transplant. The leaves can be used as mulch around tomatoes and potatoes. Cover it with leaf mulch. Comfrey has a lot of minerals in it, trace minerals as well as the major minerals. Their long tap roots draw up nutrients from deep in the ground. It helps the compost pile to decompose plus adds its own dose of fertilizer to the pile.
You can make a potent tea from comfrey leaves. Put a bunch of leaves in a plastic container. Add water and let it ferment 3-5 weeks. Be warned, it will smell bad. then drain the liquid from the mix and dilute it with a lot of water. Pour it around your plants, especially tomatoes, potatoes, and peppers. Growing comfrey right next to the compost pile is wise, as you can dig in any extra leaves. Once your plants are well established, you can harvest leaves 4-5 times a year.
Medicinally, comfrey is known as “knit bone.” It has healing properties to broken bones. I saw a two year old girl with a broken femur. Her parents made poultices from comfrey. The X Ray technician could not believed the bone healed so quickly.
Get yourself some comfrey root cuttings and start growing your own fertility for your heirloom vegetables.