Rotten stinking … but this manure is liquid gold

Russian comfrey at Gardeners Call

Comfrey grows rapidly and can be harvested regularly

It stinks! No point beating about the bush when it comes to the liquid manure I’m brewing behind our allotment shed.

 Any unsuspecting veg thief will undoubtedly scarper once he gets a whiff of the comfrey liquid bubbling away in an old plastic dustbin. How odd that something that is actually so full of goodness can be so gut-wrenchingly vile!

Having last week banged on about the necessity of making your own compost, I feel I need to add to the picture with an introduction to an extraordinary plant. Comfrey is an invaluable addition to any compost heap — but it will also give you free liquid manure packed with the potassium that many soils lack. And you can harvest it on a cut-and-come-again basis right through the growing year.

Comfrey as a cure

Quite apart from that, this superplant has great medicinal qualities. It’s excellent for grazes, and far better than a dock leaf for nettle stings. Just spit on a leaf, rub it between your fingers until it starts to break up and then apply. Apparently it is even good for knitting broken bones.

But let’s stick with the gardening benefits. The magic of comfrey lies in the fact that its deep roots suck up masses of nutrients that then quickly break down as compost, so swiftly returning the goodness to the soil.

 For most soils, nitrogen isn’t lacking to any serious degree and applications are often overdone, with the result that plants grow too quickly and are then vulnerable to disease and insect attack. Where comfrey can be invaluable is in replacing depleted potassium. The signs of that are a blueish tinge to older leaves and yellowing between the veins. This often leads to stunted growth and failure to produce fruits and flowers.

Great addition to compost heap

Phew liquid manure at Gardeners Call

I decant my comfrey manure into a plastic barrel and then dilute into milk bottles for use

On the compost heap, it helps to accelerate the rotting process but it also attracts beneficial insects and is an excellent mulch, weed suppressant and moisture preserver around plants.

The liquid manure is best made by packing crushed leaves into a hessian sack and tying the top. Pop the sack into a large bin, anchor down with a brick and fill with water. Make sure you stick a lid on it or you will certainly upset your neighbours! If you feel you do need to boost up nitrogen levels add in some nettle leaves.

Let it brew for two weeks to a month and you will have what is commonly known as comfrey tea … though you won’t want to drink it. Decant the liquid into a milk bottle and then dilute to about 10:1 as you need it. It may stink but its great as a tomato feed and also to boost up any sickly looking plant.

Handle with care

 If you decide to buy yourself some comfrey plants, it’s best to go for Russian comfrey (defined as Bocking 14) as others seed everywhere and are invasive. Use gloves to handle them as the tiny hairs on the leaves can irritate sensitive skin. Divide it every couple of years for extra plants, and don’t worry when it disappears in winter as it will re-emerge.

One final word of warning. Don’t spill the liquid on your clothes as you may need to burn them!