Comfrey is a very valuable plant to have in an organic garden, because it grows very vigorously and can be used to feed other plants. Comfrey has very deep roots that bring up nutrients from the subsoil, which are then stored in the leaves. Comfrey leaves can be used as a nutritious mulch or compost activator, but they can also be turned into a free fertilizer for your tomatoes and other fruiting plants.
- Harvest your comfrey. Comfrey is a very vigorous plant. Once it has established in your garden, you will be able to harvest the leaves several times throughout the growing season. Simply cut the leaves right back and gather them up.
- Put the comfrey in a bucket. To make liquid feed from your comfrey, you will need a bucket with a lid. If it has a tap as well, that makes life easier later on. Stuff your comfrey leaves into the bucket -- cram in as many as you can.
- Weigh the leaves down. Put a brick or stone on top of the leaves to weigh them down.
- Don't add water. Many recipes for making comfrey liquid feeds advise adding water, but when comfrey leaves rot down in water, they make a horrible smell. If you don't add water, the leaves will still rot down -- but they won't make a big stink about it!
- Put the lid on. Put the lid on the bin to keep the rain and bugs out.
- Wait 6 weeks. Comfrey leaves will take a few weeks to rot down -- you can keep checking on the progress, but expect it to be about 6 weeks before they're finished decomposing.
- Drain off the liquid. Drain off the liquid feed -- it will look a little like a dark brown syrup and have very little odor.
- Put the comfrey leaves in the compost. The remains of the rotted comfrey leaves can be added to the compost.
- Start again! If your comfrey plant has grown a new crop of leaves, then you can start the process over.
- Use your feed. Your comfrey liquid needs to be watered down 15:1 before use. It is high in potassium, and makes an excellent feed for flowers, tomatoes and peppers.
Don't worry if your comfrey plant flowers before you cut it -- the flowers will attract bees to your garden and you can still use the leaves.