The “compost leaves” page of Carry-on Composting has been revised to give an increased information on composting  holly as in addition to being a garden compost problem  it presents an annual challenge when disposing of holly as part of the Christmas decorations.

 In the UK, the general advice seems to be that leaves should be used to make leafmold rather than compost but in the USA, leaves  seem  to be considered one of the most reliable sources of winter browns and I have found dry autumn leaves as an excellent source of browns for the allotment compost  bins over the winter.

All leaves are not the same and the type of leaf available may influence the choice of whether they are used to make leafmould or compost.

Ash, cherry, linden, maple, popular and willow are relatively low in lignin and relatively high in nitrogen and calcium and compost relatively quickly.   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. In addition to the lignin content there is another problem with holly leaves is that the  waxy coating on the leaves provides  a protective outer layer preventing water loss which makes it important to shred these leaves and to only  compost them in small amounts spread across several bins if possible.  However, as it can still take up to two years to compost holly, so it is best to use a dedicated bin. When large amounts of Cherry laurel are shredded a smell of  smell of almonds or marzipan, can sometimes be detected and concern has been expressed about the risk of cyanide poisoning.  The safety precautions are not complicated i.e., chipping, or shredding it  in a well-ventilated area and not standing downwind while working.  

 As a rule, leaves being used for composting or making leafmold  should be shredded  as this exposes a greater surface area, reduces the risk of the leaves matting  it also  reduces the bulk of the leaves making composting easier. At Christmas, I also shred the holly wreaths and compost  them with the saved autumn leaves or add them to the leafmould bin.

Mixing the leaves with grass or another good source of nitrogen will speed decomposition. If a shredder is not available two processes can be combined by spreading the leaves of the lawn and mowing them.

To cold compost leaves in a dalek type bin , use 50-70% (by volume) leaves and 30-50% of high nitrogen ensuring the carbon rich leaves are well mixed with the nitrogen rich  food scraps, vegetable leaves,  grass etc.  and other materials in the bin.

 If hot composting leaves, the  compost bin  should  be at least one cubic meter, but preferably bigger,  to retain the heat and help the leaves decompose more quickly. 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 alternat 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.   An alternative method is to make a normal layered compost  pile using  layers of   4-5 parts leaves to one-part green garden or kitchen waste. The material is initially mixed and aerated 1-2 times a week. Additional greens can be added when the contents are turned to prolong the active stage and maintain the temperature.  

More information is given at ( http://www.carryoncomposting.com/142941489) or by clicking Composting leaves.

I have updated the Carry-on Composting  page on rats. http://www.carryoncomposting.com/416920198)

This is the equivalent of 12 A4 pages and gives an overview  as well as specific actions to help deal with the rat problem. 

Rats are commensal rodents the numbers of which are influenced by our activities, buildings, and the landscape we have created. The type, style age and size of our houses and gardens and what we do in them will also impact on the number of rats. Some activities such as keeping chicken, feeding the wild birds, and composting using an open heap may be beneficial to the rats while others such as keeping cats or terriers may discourage them.

Although many gardeners and composters will only see rats infrequently, if at all, a study conducted in central New York reported that pests, including rats, were the third most common obstacle to home composting (Tompkins County Compost Study. Prepared by: Cornell Cooperative Extension’s Compost Education Program 2001). Undoubtedly opening a bin to find a rat sitting on the composting looking at you can be a disconcerting even if it only happens once.  While rats may visit, or nest in, a compost bin if they are already present in the area composting does not generally attract the rats in the first place. 

When rats are feeding, sheltering, or nesting in a compost bin burrows 30-40mm in diameter can often be seen under the bin or holes are visible chewed into the side of the bin. Rats are attracted to compost bins and heaps as a source of food, shelter and as a warm dry place to nest. The compost bin will be particularly attractive during the winter as it can provide warmth and a good supply of food with kitchen scraps being regularly added to the top while the material in the lower part of the bin is relatively undisturbed.  Rats need to gnaw hard surfaces to keep their teeth under control as they grow throughout their lifetime so many wooden and some plastic bins will offer little obstacle if the rats smell the decomposing food inside the bin.

The signs of their presence in the rest of the garden are also relatively easy to detect.

The Norway rat creates burrows and makes “rat runs” along building foundations, garden fences and walls. They will also burrow beneath chicken houses, woodpiles, manure, and compost heaps. Nests in compost heaps or bins may be lined with shredded paper, other dry material from the heap or material brought into the bin. The contents of the compost bin make a good restaurant for brown rats as their preferred diet includes cereal grains, nuts, and fruits, meat, and fish.

The Black rat seldom digs burrows preferring to nest in locations off the ground in dense vegetation, shrubs, trees, vines etc. They also eat a range of foods that might be found in the compost bin. There preferred diet consisting of fruits, nuts, berries, slugs, and snails. 

The information on the website includes:

 Signs of Rat Infestation,  Reducing the risk of rat infestation,  Weil’s disease,  Location of the bin, Material being composted and rat infestation, Regular Human Interventions, Rats and Compost bin design, The Bin Contents, Rat Shelter and nesting in the compost bin, Rat Infested bins, Making the garden less rat friendly,  

Other suggestions and rat poison advice, Selected Sources, and further reading.

Most home composters will save their kitchen waste in a solid sided plastic box or a purchased kitchen caddy.  These are available with or without a filter to reduce and/or with an airtight lid. Details can be found at www.carryoncomposting.com/443725798

Ideally the caddy would be of a size that needs emptying into the compost bin every few days to avoid the material decomposing or going mouldy. These caddies are easily cleaned and are often suitable for washing in a dishwasher. Home composting is the environmentally preferable method of dealing with food waste  but if you do not have a suitable compost bin for cooked food waste and cannot treat it using a Bokashi bin using the Council food waste collection is much better than sending the waste to landfill.

However, if you are taking advantage of a Council kerbside collection system you will be required to follow their procedures and the use of a ventilated caddy with a compostable liner is increasingly becoming the method of choice.

When transporting material by road journey weight is an issue especially if it is being weighed at the end of the journey.  The weight loss by evaporation in a ventilated caddy can be as much as 30% in the few days it is waiting for collection.  Evaporation and airflow through a ventilated caddy has the additional advantage of reducing the likelihood of the material starting to decompose anaerobically and reduces the risk of unpleasant odours.  In addition, the condensate that can accumulate at the bottom of traditional closed caddies is avoided.  This system also offers the additional convenience to the householder in that the caddy will not need to be washed after each use.

 Containing the food waste in compostable bags also offers advantages across the collection, transport, and composting systems and one council has estimated that the use of compostable bags for the food waste was twice as efficient as the next best food collection scheme, which did not use bags. 

So, the advice is:

• If possible, home compost your waste food (See www.carryoncomposting.com/ 443725798)  
• If this is not possible take advantage of any kerbside food collection available.  

The general advice is that weed seeds should not be composted  as  while weed seeds will be killed hot composting providing an adequate temperature is maintained they will usually survive cold composting techniques and the advice is Do Not compost them. The problem is that if they survive the composting process, they will be in the compost you spread  as  a mulch soil improver and you will end up with a  crop of weeds.  Hence the advice not to add the seeds to the bin by  pulling up the weeds before they seed  but when community composting you may not have the choice others will fill your reception bin with weeds that are in seed.

When hot composting at 55^oC for a week will  most weed seeds and a month at 63 ° C) will  kill the most resistant one as well as their roots. Amongst these resistant seeds are those of Common groundsel (Senecio vulgaris) which are shown in the photo.

 However, many garden  or allotment compost bins   will not be large enough to reach and hold the right temperature and/or   turned often enough to expose the seeds to the hot core of the compost. Exposing all the compostable material to sufficient temperature even when community composting with a large bin turned requires good  management of the system and dedicated volunteers.

There are many composters who are accept that we weed seeds will  survive as they “have a hoe” and are happy to deal with the seedlings as they germinate,

There  is however another approach. Larry Hodgson  the Laidback Gardener

 (https://laidbackgardener.blog/2018/08/26/how-to-kill-weed-seeds-in-compost/)  suggests the use of solarization to kill seeds at the end of a composting cycle by spreading a layer of compost on a hot sunny surface and covering  it with a sheet of transparent plastic, held in place with bricks or wood. The compost will heat up in this mini greenhouse killing the seeds or any seedlings  that germinate. This technique is dependent on hot weather and will require a suitable space.

One of the joys of community composting where organic materials are dropped off by members  is that you never know what  you will find in the Reception bin or how much understanding of composting those delivering the materials will have. This week is a case in point  I had a load of stinging nettles amongst the other waste. These had reached full hight and had been pulled up so that the roots where included. As the roots will survive cold composting and may survive hot composting if high enough temperature is not held  it is better to separate the roots form the plants. The roots can then be dried and composted once they are dried up and dead or drowned.  On this occasion I am drying them on the rack shown which will be covered . This rack consists of old bakery trays rescued from a skip  at a local pub  and allows several layers of roots to be dried.

If pulling up nettles from your own plot it is easied to cut the tops off before pulling them up compost the tops and then pull up the roots. 

The remains of the plants can be chopped up and used to form a green accelerant  layer in the compost bin.

Details of drowning nettles and other plants  to make liquid feed are given at : http://www.carryoncomposting.com/142941460

 The photo shows some of the  roots on the rack at the tops ready to be taken to the bin and cut into short lengths.