If you enjoy a Sunday walk in, say, your local Beech wood, then its continuing vitality is primarily down to nature’s own recycling – leaf mould. Far from being worthless, fallen leaves are nutrient rich and, once rotted down, are excellent for mulching, top dressing, improving soil texture – even for potting… The good news is that any leaf or needle will decay into productive leaf mould. The even better news is that the leaves of two of the most popular hedges – Beech and Hornbeam – are renowned for producing the finest quality leaf mould. Only Oak leaves can match (but not better) these two.
What is Leafmould?
In a nutshell, Leafmould is compost made entirely from (fallen) leaves.
The first thing is to recognise that when it comes to Leafmould, there are four types of leaves:
1) Thin, deciduous leaves epitomised by Beech and Hornbeam that decay easily and quickly
2) Thicker deciduous leaves (e.g. horse or sweet chestnut sycamore, walnut, etc.) are best shredded first as they take longer to decompose when intact. Once shredded, they can also be added straight to a general compost heap
3) Evergreen (e.g. Cherry Laurel, Holly etc.) also needed to be shredded and though they will produce usable Leafmould, they are perhaps better sent to the general compost heap where they will compost quicker
4) Conifer needles (e.g. Leylandii, Thuja plicata atrovirens AGM etc.) take anything up to three years to rot down, they are also best sent to the general compost heap
N.B. If you also grow ericaceous plants, Pine needles make an excellent acidic Leafmould – give them a pile on their own!
When to (Start) Making Leafmould
(But collect Pine needles throughout the year.)
How to Make Leafmould
Once you have collected your leaves either:
A) Place them in a bin liner and moisten if dry. Tie the bag loosely and pierce the bag (a garden fork works well) in several places. Stack the bags somewhere out of sight and come back in a couple of years
B) In a sheltered, out-of-the-way place, make a round or square frame (stakes and chicken wire for example) and fill with the leaves. The larger the pile, the faster it will compost – but it will still take two years. Turn every couple of months and moisten during hot/dry periods.
NB: You can, of course, collect additional leaves from public places but avoid main roads as the leaves will have been polluted.