Peter Dowdall: Why comfrey is your garden's wonder plant 

If you grow comfrey, you will have a ready supply of ingredients for high-nitrogen plant food 

Comfrey is used as a plant food and herbal remedy, and its flowers are loved by bees. Pictures: iStock

It starts off as an unassuming-looking plant, but before long one small symphytum will have colonised a large part of the garden, pushing other, weaker inhabitants out of its way.

Don’t let this put you off choosing it, though. Better known to you and me as comfrey, symphytum is a wonder plant. It takes nutrients from the soil and then stores them in its leaves.