An excellent natural fertiliser - good as a compost activator, a mulch to feed the soil, and for making liquid feeds.   Some background on Henry Doubleday, Lawrence Hills, with useful comparisons and tips for using comfrey, from John Harrison's site.

• The roots go 3 metres deep, and draw up nutrients from the subsoil.
• The leaves hold high levels of nitrogen, phosphorus and potassium.   A better source of potash (good for potatoes!) than farmyard manure.
• Comfrey also has remarkable healing properties.

Once established, a comfrey bed will continue producing leaves for many, many years - and it requires little effort.   The Chase/HDRA Organic Catalogue offers a variety, Bocking 14, developed specifically for garden use.

Two words of caution

• Other varieties (and wild comfreys) set seed wildly - and take over!
• Comfrey (including Bocking 14) has very deep roots; and it will grow from snippets of broken root.   Once established, it will be hard to move to another part of your plot; choose your corner with care!

How to Grow

• Choose a sunny spot, with deep soil, in spring or autumn.   Dig in manure or compost, and clear any perennial or invasive weeds.
  • A spring planting will give you 1 or 2 "harvests" in the first year.
  • An autumn planting will give you (perhaps) 1 "harvest" in the first year, and 4 the second.
• Plant the plants about 24 inches apart, and water them well.   The plants will need watering while they are getting established.
• Mulch with manure every spring.
• Once well-established, the plants will require very little attention.   Cut the leaves regularly - 4 times a year, if you do not allow the plants to flower.   When the plants are at least 12 inches tall, wearing gloves (the hairs on the leaves can be an irritant), cut the leaves to 2 or 3 inches above ground with a sickle or a scythe.
• After a couple of years, you can start taking root cuttings to propagate further.

Using the leaves

• Let the leaves wilt overnight, then
• Dig them in - 2kg of leaves per metre; as good as fertiliser or compost.
• Lay a good layer in the bottom of your potato trench at planting time.
• Mulch - lay the leaves about 2 inches deep on potatoes or tomatoes; good for feeding, but not for suppressing weeds.   And do NOT include any pieces of root or stem - or you will have a new weed!
• Composting - adding a layer of leaves will get a   s-l-o-w   compost heap working a lot faster.
• Best of all?   Liquid Manure

Nettles

You can make a similar liquid feeds with nettle leaves - especially in springtime when they are richest in minerals.   Use the same recipes as for comfrey.   Nettles are also a good source of nitrogen for a compost heap - gets the rotting process going.

Nettles will continue to grow back if you take two cuttings a year; if you want to get rid of the nettle patch completely, take four cuttings a year, and in time the bed will disappear.