Wool waste (shoddy)   from textile mills has been “composted” by farmers since the start of the industrial revolution. Originally it was left to breakdown in contact with moisture in the soil and it  is worth remembering that  wool does not need to be composted to be a useful growing medium and source of nutrients. Simply burying wool produces benefits and it is particularly useful in pot-plants where adding wool to  the   growing substrate can result in  higher yield.  A  newer use  use is in making  commercially available peat-free compost often with bracken .

Untreated and uncleaned fleeces with  faecal matter (daggings) still attached to the have the bonus of containing  dirt and faecal although this makes them less pleasant to handle and may contaminate the hands with pathogenic organisms.  When used in the preparation of compost sheep wool offers improved water and a supply of  nitrogen and trace elements. a wide variety of materials can be used to compost with wool, including wood and bark, green waste, animal manure and bracken.

  Most home composters will be aware that old garments made of wool and other natural fibres can be composted. Linen and  Hemp  are the quickest to breakdown followed by cotton. Wool (including alpaca)   may take about a year,  while silk takes longer. If added to a conventional household compost bin it is important not to let the wool dominate the mixture using it only in moderation.

  The use of an appropriate composting method e.g., hot composting with the right mix of other feedstock  can speed the breakdown while treatments during manufacture of garments may prolong it. Wool contains about  10% of nitrogen which is released slowly into the soil. When composting the wool should be cut into small pieces (packaging wool is easily torn)  garden  plants or other greens  are normally  added to the bin and mixed  at the same time as the wool if using  a dalek or similar  type of bin. I often  add a thin layer of manure in our pallet community bins which will be turned to aerate. It is best  not to exceed  25% by volume of wool in the bin. Old wool bedding, which cannot be recycled, can also be composted at the end of its life  as bedding.

Sheep wool is now available as packing liners to protect fragile items. I have used Puffin packaging compostable sheep’s wool in a recyclable “plastic” bag. Two or three strips of the wool from packaging is sufficient to form a wool layer in a pallet bin when torn up. Tearing up the wool before composting avoids clumping and the possible formation of anaerobic lumps. It also  makes it easier to turn compared with leaving it in the original  sheets. During the  dry summer  I  incorporate three layers  of packaging in our  current working  bins, plus coffee grounds (because we have them)  in the hope that the wool will improve water retention in the hot dry weather.

If composting larger quantities of wool one of the suggested  mixes is 25% wool. 50%  grass cuttings, 25% stable manure (horse manure  was originally used but mature cow manure might be safer as it is less likely to contain herbicide). A smaller proportion of wool  with more manure  also works. If grass clippings are not available wood chip can  used but the mix is slower to compost. Additional greens should speed decomposition.

The photos show Puffin packing being composted in a pallet bin of normal allotment waste. I have also used Woolcool brand. The bin was initially only half filled as I run out of time but it was at  themophilic temperature  before being completely filled a week later.

  Day 12. The bin was uncovered and the contents turned. The wool was little changed but there was a considerable amount of actinomyces present. These bacteria have appeared early  in three of the other bins in this row of 5