9. Nov, 2017

Making Leafmould

 While a pile of leaves left in the corner of the garden will eventually be broken down by fungi to form leafmould a considerable proportion of them will be spread across the garden by the wind. To avoid this situation the leaves have traditionally been contained in a wire netting cage or wooden compost bin. As with composting larger bins work best so try to make your container at least metre square. Simply fix the chicken wire to four posts with galvanised fencing staples available from any builder’s merchants or DIY store

  For best results the pile should be checked during hot or dry periods and watered if necessary to  keep leaves damp sand the  moisture content high enough to help decomposition. Turning the pile occasionally to aerate it will also help.

  Plastic “cages” are also available but the simplest form of plastic container in which to make leafmould is a large plastic sack. The leaves are soaked; the rain will normally do this for you, and placed in a bag, which is then stabbed with a garden fork. The bags are left in a corner of the garden for two years and the leaves magically turn to a rich dark leafmould. I would recommend using old compost or rubble bags as the thin black plastic bag left in the garden is likely to become brittle and disintegrate before the leafmould is ready. The use of a porous builders bag/container with its handles tied together has been recommended by John Walker writing in the Daily Telegraph.

 Shredding and urine accelerator

  Shredding the leaves using a garden vacuum will reduce the size of the leaves and speed up the composting process.  An alternative means of shredding is to spread the leaves on the lawn and mow them (and the grass). This provides a carbon (leaves) and nitrogen (grass) mix which further reduces the time taken to compost. Grass can also be added to the leaves shredded using the garden vacuum to speed up the decomposition

 Urine makes an effective accelerator and can be applied directly by men or for the more discretely collected indoors and taken to the bin or bag.

 Coffee grounds as an additive for leafmould

One of the reasons that we normally make leafmould separately from compost is that the leaves are a Brown being high in carbon. It is possible to speed up the decomposition process by adding, nitrogen rich, and grass using the technique of shredding the leaves by mowing them on the lawn which will speed up decomposition of the leaves.

An alternative method of speeding up the process is, if you have access to a local coffee shop, restaurant or cafe, is to add used coffee grounds to the leaves. Coffee grounds contain about 1.45% nitrogen making them a useful Green which can also be added to wormeries and the compost bin.

Many coffee chains now bag and give away used grounds to composters. While some outlets might limit the number of bags each composter can take it is quite likely that an arrangement can be reached to have a regular bulk supply and a local independent outlet may be happy to have a source that will to take their whole supply.  

 Comfrey enriched Leafmould

Comfrey can be used to make leafmould with additional nutrients. Comfrey is added to two year old leafmould two or three months before it is to be used. This is best done by transferring the leafmould to a new container with a layer of comfrey leaves added every 10cm/4inches. Although it requires some effort it produces a relative consistent product.

An easier method is to mix comfrey with the leaves as the leafmould bag or container is being filled in the autumn. 

 Composting leaves

  All leaves are not the same and the type of leaf available may influence the choice between composting and making leafmould.

Ash, cherry, linden, maple, popular and willow are categorised as “good leaves” by Ken Thompson in "Compost"    composting  down in about a year  being relatively low in lignin and relatively high in nitrogen and calcium.  He classifies beech, birch, oak and sweet chestnut as bad leaves being higher in lignin and lower in nitrogen and calcium and taking at least two years to compost. More information on the types of leaves can be found here Leafmould

  An alternative to adding the 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. A variation on this technique is to use a mower to shred the leaves on the lawn when the grass need cutting so that there are about equal quantities of grass and shredded leaves.

 Compost made using Pine needles is acidic and as consequence their compost is recommended for acid-loving plants such as strawberries, raspberries, and rhododendrons.  However the leaves take longer to decompose than most other types so should be composted separately. I would always recommend shredding them first.

If you only have space for one compost bin pine needles can mixed with the normal compostable waste but I would recommend that they do not exceed 10 percent of the content. However the composting leaves in a conventional heap or bin can be a slow process. 

 Hot composting using a Hotbin composter provides a quick and effective means of composting shredded Leylandii and pine needles producing compost in about 3 months if the temperature is maintained.

 Alicia Bodine in a Home Guide by Demand Media recommends the following composting method.  Starting with an empty compost bin fill approximately 8 inches grass clippings, or any other green waste from plants in the garden. Water until moist but not sopping wet. Add a 3-inch layer of pine needles, repeat the watering and then add a 1 inch layer of horse, cow or chicken manure. Water again. This layering of grass, pine needles and manure is repeated until the bin is full. The bin should be watered to keep it moist and the compost mixed to aerate it once every two weeks. The compost should be ready for use in about two to four months.



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.


Collect autumn leaf fall into old plastic compost  sacks or bags as normal but do not soak the leaves as would normally be the case if leaf mould is being made .The use of dry leaves in the Bokashi leave composting system is said to avoid the bags  smelling during the composting process.. Seal the bags with a tie or clip which can be released and resealed during the following months. During the winter open the bags and add the contents of the Bokashi bins as they become available. If the leaves in the bag are damp, add newspaper or shredded paper to absorb the moisture

During the spring, the sacks should be moved to a sunny part of the garden or be moved to the greenhouse so that the warmth will encourage activity of the microbes in the Bokashi and the original autumn leaves. The

This will produce a mulch for use early in the season or a more useful compost mix after a later in the summer.  At this stage, the bags can be stabbed with a fork to create air holes and entry points for worms. These holes will also provide drainage.