Cheap but brilliant fertiliser!

Comfrey grows like a weed in my garden but I love it! It looks rather like pulmonaria without spotty leaves but the whole plant is a brilliant mulch and rotted dow a stinky but stunning fertiliser

My comfrey is the wild sort but I don't mind it being round the garden!

Grow Your Own Fertiliser Using Comfrey  written by Jeremy Dore 
Achieving Horticultural Excellence
When it comes to feeding plants, nothing beats organic compost.  Good compost contains the ideal range of nutrients which are released slowly into the ground as plants need them.  
Comfrey is a large herb, native to Europe, which grows prolifically in damp places such as river banks.  As such, it can easily get out of control in a garden, so would not normally be deliberately introduced.  However in the 1950s the organic pioneer Lawrence Hills (founder of the organisation now known as Garden Organic) developed a strain of Russian comfrey named Bocking 14 which is sterile and will therefore not seed itself all around the garden.  To propagate it root cuttings are taken although these are best bought from a reputable supplier (such as the Organic Gardening Catalogue in the UK) to ensure that you get the Bocking 14 variety.  It easily roots and grows very quickly so it is best to plant it in its own bed to prevent it taking over an existing area.  [A word of warning: wherever you grow it don’t ever expect to eliminate it as its root system is very hard to kill]

There are many great ways to use comfrey around the garden:

• Mulch: Leaves can be cut and left to wilt for a couple of days before piling them around hungry plants such as potatoes and tomatoes as a thick mulch.
• Dig in: Wilted leaves can be dug into ground that is being prepared for a new crop and will break down to give an excellent feed.
• Liquid Fertiliser: Comfrey leaves can be crammed into a large container with a hole in the bottom with a small container underneath to catch the thick black liquid which will be produced in a few weeks.  Weighing the comfrey down with an old brick will help this process and some people add rainwater but this does make the resulting ‘comfrey tea’ smell awful!  Once produced, the liquid should be diluted 15:1 with water before using it as a leaf feed for plants such as tomatoes.
• Potting Soil: Comfrey leaves can be shredded and mixed with leaf-mould to produce a balanced soil for plants in pots, although it is a little strong for young seedlings.
• Compost Activator: Adding high-nitrogen sources is a great way to boost ‘hot-composting’ if you have the right balance of green and brown shredded material.  Comfrey, being high in nitrogen, is ideal for this and should be well combined with the whole mixture rather than adding it as a layer.

So. Comfrey really is nature’s answer to fertiliser for organic gardeners and best of all it is free – the perfect plant supplement you can grow yourself.