Comfrey has to be one of the most useful plants to grow in the garden, and not least because it is a fantastic natural fertilister.
Russian comfrey (Symphytum x uplandicum) and in particular the variety ‘Bocking 14’, is suitable for growing your own fertiliser. It reaches over several feet high but as it doesn’t set seed it won’t take over the garden!
Plant in a sunny position, ideally in a permanent location as it can regenerate from pieces of root left in the soil. Space plants 3ft apart.
Do not cut in the first year. Once established, harvest the foliage four times a season. When the leaves reach to around 2 ft high you can cut it back.
Store the liquid in a cool, dark place. To use as a liquid feed dilute one part concentrate to 10 parts water.