Comfrey is a vigorous grower, and difficult to get rid of once it has established itself, so choose its spot carefully. Most allotment gardeners plant this close to their compost bins, and since it will cope with most soils, and is happy in full sun or partial shade siting it near the composting area is rarely a problem.
Comfrey will grow to around 50cm-1m high with a spread of around 60cm, and produces attractive pink flowers in summer. Buy pot grown plants from a nursery and plant out in their final position.
Comfrey leaves can be harvested 3 or 4 times per year, just cut them with shears.
Plants can be propagated by division or by root cuttings.
Comfrey Tea Recipe
This is the most common use for comfrey. You will find numerous recipes, but here are the most common methods of making this fertiliser.
Comfrey Tea 1
Add comfrey leaves to a water butt or tapped container at a rate of about 6kg to each 100litres of water. Top up the butt with rainwater (don’t use metal containers as they will rust due to the amount of iron oxide in the fertiliser) and then leave for 4 weeks before use. Simply drain the liquid from the tap and use as a feed for your tomatoes, peppers, or any other fruiting or flowering plant.
The disadvantage of this method is that the liquid does smell (comfrey contains a high amount of protein, and protein smells when it decomposes) and is difficult to contain this smell from a water butt.
Comfrey Tea 2
This method produces a more concentrated version, that can be diluted for use. The advantage of this is that you can seal the concentrate into a bottle containing the smell between uses.
Cut the bottom off a 2l pop bottle and stuff it full of comfrey leaves. Keep the bottle upside down (with the lid on) and top up with water. Leave this (dig a small hole and support it in the ground) until it turns into a smelly slurry, and then open the lid and strain into a clean bottle and seal.
This should then be diluted 10 parts water to 1 part fertiliser before use.