Comfrey is rich in potassium (K), which is required for fruit production, and also contains potash (P) and nitrogen (N). A liquid comfrey feed has a higher NPK ratio than farmyard manure. Comfrey is also one of the few plants to contain vitamin B12, so it’s a rich source of food for plants.
Wear gloves when you pick comfrey, because the hairs can irritate. A mature plant can be harvested around six times a year, from spring to autumn.
Make your own liquid feeds.. as well as being more economic, you can be sure that they are 100% organic.
I suppose the classic organic liquid feed is Comfrey Feed and there are two ways to do this anaerobic and aerobic.
This is the anaerobic way, (The smelly way!) that is no air involved. Simply steep comfrey leaves in water in a plastic bin with a lid, weighing down the leaves with a brick for 10-14 days. When it starts to really stink then it’s ready. Draw off the liquid, dilute 1 part concentrate to 3 parts water, (So approx 300ml per litre) it should be the colour of tea.
Comfrey Concentrate
This is the method I prefer and use it is aerobic (so no water, just air) and it’s virtually odourless. Harvest your comfrey leaves from established plants, the hairy leaves can be a skin irritant, so wear gloves.
Remove flowers and tough stems then chop up the leaves and pack tightly in a plastic bin with a lid, weigh down the leaves as above. Preferably the bin should have a tap or hole in the bottom to draw off the resulting liquid. The comfrey leaves decompose slowly producing a thick brown liquid after about 2-3 weeks.
Dilute 1 part comfrey concentrate liquid to approx 20 parts water.(So approx 50ml per litre)
A standard 10-litre watering can, that’s about a half a litre of concentrate.
Comfrey leaves are an excellent source of potassium, essential for flowers and fruit to set. Use for your tomatoes, peppers, strawberries, courgettes & beans.