A "comfrey tube" plus plants being soaked in buckets, bin and Bokashi bins
The traditional method of making plant food by soaking the plant material was to weigh the leaves down in the bottom of a bucket or water butt with a stone and wait until it decomposed. Ideally the container would have a lid as the product would have
a strong unpleasant odour. I understand that the technical term that they stink.
However, as gardens have become smaller with less material to turn to food and space to hide an extra water butt several small commercial systems have come on the
market and then dissapeared.
On our Composting Demonstration site, at Stokes Wood Allotment, Leicester, we use lidded nappy buckets for demonstrating the use of small volumes of plants such as dandelions and horse tail so that
visitors can see the decomposition in progress.
Mixed weeds being killed are soaked in a dustbin while the plants used in larger quantities being soaked to produce feeds e.g. comfrey is soaked in old Bokashi bins or water
butts enabling the liquid to be run off while most of the sludge remains in the bin. It helps speed the breakdown if the liquid is stirred vigorously every day of two.
There is a difference between making Plant Feeds by soaking and drowning
perennial weeds to kill them to make them suitable for composting. The process of drowning perennial weeds will require soaking over weeks, months or even a couple of years(?) to kill weeds while soaking leaves and green shoots to make a
liquid feed will only take days or two to four weeks (depending on the technique and equipment). When making liquid feeds only the young green parts of the plant are used carefully avoiding the use roots of perennial plants and
seeds which may survive the process if the sludge is added to a cold compost heap. Chopping and tearing the greenery into small pieces will speed the decomposition.
The plant material can be contained in a plastic mesh tube or in a pair of old
tights to reduce the need for filtering the product. I prefer a commercially available compost sack, or bag, sold to be used in the making of Compost Teas If unbagged material is used and it is not filtered the sludge will block the
rose of the watering can, or spray, when being applied.
The effectiveness of the process can be influenced by the position of the buckets in the garden and of course being biological decomposition, it will occur best at temperatures favourable to the
microorganisms involved. Within the range 12°C to 25°C is best. While some direct sunlight very strong sun over a period may cause the container to fad!
Ideally rainwater collected from the roofs of sheds or greenhouse. If
tap water must be used it should be left standing for at least two days. After which the pH should be checked and a little spirit vinegar if it needs acidifying to bring it to a neutral PH.
Several commercially available systems designed for the urban gardener with a small plot have appeared on the market since this website was started and we have used three on the demonstration site and at events.
far the best ais the Hozelock Biomix which I use regularly and recommend for thos who only want to produce limited quantities of liquid feed.
A second system the Natural Plant Food maker is still advertised on Google, but marked as unavaialbe
at the time this revision was made, so I have still included details below for the present.