this is pretty large scale stuff but you can make leafmould on any scale
Before deciduous trees shut down for winter, they extract as much food as they can from their leaves, leaving a carbon-rich autumn leaf to fall. When they land, these leaves are broken down mainly by fungi to become leafmould and provide a marvellous rich source of humus.
Leafmould is a really useful material to have for potting and seed-growing media mixes. If you don’t have many leaves, just add them to your compost heap.
To make a leafmould bin
To make a simple container that will stop the leaves blowing around, all you need are four posts, set in the ground to form a square, wrapped around with some chicken wire. You don’t need a lid or anything fancy. As some leaves take two or more years to break down you might want to build more than one enclosure.
If you have only small amounts of leaves then you could just stuff them into plastic sacks – make sure they are wet when they go in and stab a few holes in the sacks with a fork. Find a place to put these sacks out of the way and the contents will gradually transform over two to three years into leafmould. (NB some leaves, e.g. plane and sycamore leaves, take longer – up to three years.)
Making speedy leafmould
If you have a mower that chops and mixes leaves with the grass you can put both into a bin, which will speed up the composting process. Or you can turn out the leafmould from the bin the following summer, mix it well with fresh lawn mowings and restack. Adding urine to your leafmould will also speed things up!
Sieving your leafmould
Once you’ve made your leafmould, if you sieve it you get the most wonderful product which you can use as an ingredient in potting and seed composts.