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 commercial systems have come on the market.
On our Composting Demonstration site, at Stokes Wood Allotment, Leicester, we use clear lidded buckets for some volumes of plants such as dandelions and horse tail so that visitors can see the decomposition in progress. This enables the
process to be monitored without opening the lids. 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 green parts of the plant are used carefully avoiding the use roots of perennials plants and seeds which will
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. A commercially available compost sack or bag used in the making of Compost Teas can also be used If it is not filtered the sludge will block the rose of the watering can or spray when being applied.
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.
There are several systems on the market the majority being made
of plastic. Choose with care, some of the lower priced models on sale a few years ago when not very robust and the plastic mesh basket designed to hold the green waste warped in use and had to be held together with rubber bands.