As I mentioned in my first ‘planning the plot‘ post, my goal is to ensure everything I plant has a ‘use’, beyond simply being ‘nice’. Comfrey certainly falls into this – it looks attractive in its own right (and the bees love it!), but that is not typically the reason it’s grown by most.
I’ve grown Comfrey before – in fact, it was one of the very first things I planted when I took on my first allotment. Most plot holders grow it for 2 purposes; as a compost activator, and to create a liquid feed. It’s excellent for both – the liquid feed it particular is invaluable.
Comfrey leaves contain nitrogen, potassium and phosphorus – all of which are needed by plants. The leaves contain three times more potassium than manure, so are especially good for fruiting plants such as Tomatoes.
Adding cut or bruised leaves in layers to your compost heap encourage bacterial action, increasing the heat and thus speeding up the composting process. The resulting compost is further enriched too.
Comfrey Leaf Mould
Adding comfrey leaves to a heap of leaves allows their nutrients to be absorbed within the mould. Leaf mould itself has little nutritional value, so this addition helps create a perfect medium for potting compost.
Liquid Feed – or ‘Comfrey Tea’
There are two ways to make liquid feed – a concentrated feed, or regular liquid feed. A liquid feed is made by adding 15 litres of water to 1kg of of cut leaves, and allowed to ‘stew’ for between 4 and 6 weeks. This feed can be applied directly to plants, in place of a tomato feed for example. Be aware however that it smells – a lot! A concentrated feed doesn’t smell quite so bad, and is made in a similar way, but without adding water. The leaves do however need to be very lightly packed into a container such as a lidded bucket or drinks bottle. A concentrated feed should be diluted 1:20 before applying to plants.
Another common use for Comfrey is to line a trench with leaves, cover with a little soil then plant potatoes or runner beans as usual. As the leaves break down, they release potassium into the soil. Alternatively, they can be used as a mulch with the same benefits – helping control weeds in the process.
Comfrey for Health and Wellbeing
Both the roots and leaves of Comfrey have been used for medicinal purposes for thousands of years. In Japan particularly, it has been harvested and used to treat conditions such as joint inflammation, burns, bruises and sprains.
In Europe, it is used to create creams and ointments to treat arthritis and gout. The comfrey plant contains rosmarinic acid which helps relieve pain and inflammation.
Comfrey may be carcinogenic, and also contains liver-harming compounds. It should therefore should never be taken orally, and some experts say it shouldn’t be used on open wounds. Historically, comfrey leaves have been used as a vegetable, though such use is no longer recommended.
Which variety to plant?
Comfrey can be found in many varieties, and can be grown from seed. However, it can quickly become invasive if you choose an unsuitable variety. It’s typically accepted that the best variety for an allotment or garden is ‘Bocking 14’, which produces minimal seeds for germination. Bocking 14 also has a higher nutrient content than the common wild variety, and is easily propagated by division.