18. Nov, 2021

Autumn Leaves: A versatile carbon source

 In addition to being used as a composting “brown”, which can be kept dry and  saved for use during the winter months   autumn leaves  can be used as a  mulch,  in a layer in lasagne composting, as  worm bedding, and to make leaf mould.


Autumn  leaves that have turned brown and fallen to the ground provide a good  source of carbon when  composting winter crops. Leaves tend to be slow to compost and some sources in the UK do not recommend their use when home composting. I ca understand this attitude when dealing with household waste, where there is cardboard regularly available,  but when dealing with winter garden waste they are a valuable resource.  Shredding the leaves will accelerate their decomposition. This can be done using  a leaf shredder or by scattering them on the lawn and mowing with a rotary lawn mower.

They can be bagged and stored dry  until required  and should be mixed, or layered with,  with a “green” material high in nitrogen e.g.  manure, grass clippings, or food scraps. If cold compost leaves in a dalek type bin, nitrogen rich  food scraps, kitchen waste such as vegetable leaves,   can be used.

If added to a compost bin, or heap,  leaves may tend to mat, and this may result in some anaerobic decomposition unless they are regularly aerated or have been shredded pre-mixed with greens

 If hot composting leaves, the  compost bin  should  be at least one cubic meter (3 cubic feet) to  retain the heat and help the leaves decompose more quickly. When using leaves when hot composting I follow a 6-8” layer of leaves with a 1-2” layer of manure as two of the  brown and green layers  when constructing a bin using alternate layers of green and browns. Others suggest using thinner layers of leaves. Some add a layer of soil between the leaves and manure. If manure is not available another nitrogen rich layer may be used  such as dried blood, or bone meal.   More information is provided at  http://www.carryoncomposting.com/142941489

Grass/Leaf Sandwich

 An alternative to adding the shredded leaves to a compost bin is to make a leaf/grass sandwich using alternative layers of grass and leaves as if you were Grass Boarding substituting the leaves for the cardboard that would be used in a grass board heap.

Leafmould Choice of Leaves

 With leafmould it is necessary to make use of the leaves that are available  and if necessary, to adjust the procedure to obtain the best result. All leaves, including conifer needles, will eventually breakdown but some will do so more quickly than others and should be treated separately. Small quantities of the more awkward ones such as holly and other evergreens are best shredded and added to the compost bin.

Traditionally leafmould was made by piling the leaves in a heap and keeping it sufficiently wet to prevent them blowing all over the garden, or by imprisoning them within a wire netting cage. However, we can now bag and  the store wet leaves for two years. Coffee grounds and/or urine can be added to speed the process. (http://www.carryoncomposting.com/142941489

The photo shows leafmould corning at our Stokes wood composting site 

Bokashi leaf compost

 There is a variation on making leaf mould using plastic sacks this involves adding the contents of the Bokashi bin to the plastic leaf mould sack containing dry leaves during the winter months. This is reported to produce leaf compost during the coming spring and summer. I have not tried this, but further details are on Jenny`s Bokashi Blog.