Starting a bin

 Any time of year is a good time to start composting but each season offers its own advantages.

Starting a compost bin in spring offers the opportunity to take advantage of the warmer weather and the increasing activity of the composting microorganisms and compost creatures. However, you will need material to start and feed your bin. Once the   temperature is about 10°C for most of the time, material can be added to the bin knowing that the composting microbes will be active.  An alternative method of determining when to start is to wait until the grass on the allotment paths, or lawn,  has grown enough to need cutting. Conveniently this will provide a regular source “Greens” to start the bin if there is little in the way of other plant waste available

 Even if you are not planning to use a batch or hot composting technique when starting a new compost bin or heap in the spring, it speeds the process if the material is turned, or aerated with an aeration tool, regularly for the first few weeks to allow air into its deeper pockets. This is particularly the case if grass is being composted as it not only needs aerating but also will require mixing with a plentiful supply of Browns e.g. shredded paper, corrugated cardboard or leaves save from the autumn.

Reawakening Existing Bins

 An existing compost bin, or heap, will reactivate naturally as the temperature rises. The materials that have overwintered will  recommence decomposing as the temperature rises, although the addition of coffee grounds helps wake up the bins just as it does us. 

 The last remaining winter vegetables can be harvested, and their tops and trimmings added to the compost bin in March, these might include Brussels sprouts, celeriac, parsnips and swedes.  The Spring pruning from blackcurrants, blueberries, gooseberries and autumn fruiting raspberries can be also composted after shredding or cutting into short lengths. As with new heap aeration will speed up the process and as the temperature in the bin increases. 

  April may provide spring cabbages, cauliflower and sprouting broccoli as well as weeds removed when preparing seedbeds. The plums and cherries pruned in April might also be available for composting.

 May should see a rise in temperature helping the compost bin to move into gear helped by the addition of annual weeds a source of fresh young “green” material. The vegetable harvest may include tops turnips and trimmings from fresh garlic.

If growing Comfrey  the first cutting can take place when the foliage is 12 to 18 inches tall. Cut about two inches above the ground.  It should be possible to continue cutting the comfrey every 10 to 30 days through the summer months.  

Spring is also a good time of year to harvest compost for use on the garden. Compost, applied when the soil is moist, can be used as a mulch once the soil has warmed up in mid- to late spring. Over wintered compost can also be used to make compost tea, a useful liquid feed. It can also be used to make home made sowing and potting compost.  

 Details of liquid feeds and home-made potting mixes and other composting information can be found on at www.carryoncomposting  

This blog is the second of two on the problem of plastics in teabags and microplastic particles in the soil resulting from composting.

In the past the main concern when composting teabags was based on the fact that uncomposted teabags spread on the garden, which had passed through the composting process are unsightly but now the main problem relates to the presence of microplastic resulting from degradation of plastic in the teabags and other plastic-coated items in the soil and in drainage water.

A recent study* has shown that earthworms can be play a significant role in transporting microplastics in soils by means of their casts, burrows, etc with the smaller particles being carried to a deeper depth which may increase the risk of the microplastic entering groundwater. As composting an area tends to attract worms should be borne in mind when choosing teabags and the subsequent treatment after use.

 Other research* has shown that polyethylene microplastics in plant litter deposited on the soil surface resulted in reduced worm growth and higher mortality. Would the same results be seen if a mulch of compost contaminated with plastic microparticles from a significant “plastic” teabags was used.

But it is not just teabags there are other plastic-coated items that might find their way into the compost bin or council waste stream that can produce microparticles. Check the label, do not confuse home compostable products with those compostable at an industrial site.  Compostable products such as those containing PLA (poly-lactic acid) do not contain petroleum-based plastics and will decompose to form healthy compost.

*“Microplastic transport in soil by earthworms” by Matthias C. Rillig, Lisa Ziersch & Stefan Hempel Scientific Reports volume 7, Article number 1362(2017)  

 ** Earthworms on a microplastics diet Julia Fahrenkamp-Uppenbrink     Environ. Sci. Technol.10.1021/acs.est.5b05478 (2016).http://science.sciencemag.org/content/351/6277/1039.1/tab-article-info

Plus

The Environmental Hazards Inherent in the Composting of Plastic-Coated Paper Products WILL BRINTON1 , CYNDRA DIETZ2 , ALYCIA BOUYOUNAN2 , DAN MATSCH2  http://www.ecocycle.org/files/pdfs/microplastics_in_compost_white_paper.pdf

The war on plastic waste is due to bring a benefit for composters according to todays Observer (26/1/18) as the COOP is in the final stages of developing a plastic free biodegradable teabag. The Coop sells 367 million teabags a year hopes to have the new bags in their shops later this year.

Teabags are used to be listed as compostable items but in recent years more and more composters have complained that the bags do not actually decompose when composted. This is because most bags now including a non-biodegradable plastic (polypropylene) so that they can be more easily heat-sealed during manufacture.  The bags may be described as ‘70% or 80% compostable which includes the tea leaves and paper element of the bag but not the plastic.  Teabags accounts for about 150 tonnes of polypropylene going to landfill, AD or composting a year in the UK alone.  

The advice when home composting has been to use loose leaf tea or if using teabags:

• tear open the bags before putting them in the bin
• or sieve or pick them out after composting
• or best of the bunch  buy compostable bags

Compostable teabags made of a corn starch (SOILON) are sold by the Brew Tea Company and Teapigs. These will hot compost in about 6-8 weeks around 12 months in a cold composting system.

Pukka Tea teabags are sewn shut by machine with cotton thread, not heat sealed, and do not contain plastic. The teabag paper is made of a blend of natural abaca (a type of banana) and plant cellulose fibres.

Fruit, herbal and green tea ranges may already use a compostable tea bag material which can be put straight in the compost bin.

Paper  is almost a prerequisite for modern home composting but not all paper is the same and some is better recycled than composted.  Where paper material is both compostable and recyclable the latter is usually the better environmental option as it reduces the need to fell trees. Making paper from recycled material also requires less energy and uses less water than making it from timber.

There are those times however when home composting is the better alternative provided the right bin or technique is used. There will be some waste e.g. where cardboard is contaminated with food materials which would contaminate the recyclable waste stream if put into the kerbside collection system operated by councils e.g. greasy take-away  boxes. Home composting is much better than the alternative of sending it to landfill. However, home composting all household paper using bins may not be practicable due to the volume produced and it may be necessary to consider other methods such as Lasagne or sheet composting if space is available. Home composting can deal with some types of paper, such as tissues and shredded paper, which in many areas cannot be recycled or composted via the council kerbside collection there will still be some paper items that at present have to be fed into the council landfill system.There aretwo freuent areas of discussion on forums windows envelopes  and inks.  Concern is often expressed in some forums that printing inks are toxic and therefore printed paper should not be composted, this may well have been the case in the past, but these are now banned, and modern vegetable inks are safe to compost. The situation on envelpoes varies with the material from which the window is made and the policy of the local council. For more information go to http://www.carryoncomposting.com/416920203

Most composters will never see a rat  in their bin but  the fear of rats, and other  pests,  is the  third most common obstacle to home composting. There has been some discussion of the topic on Facebook little has been written giving an overall approach to the problem. There is now a page on  www.carryoncomposting giving information on positioning the bin to reduce the likelihood of infestation, the signs of infestation, bin contents that attract rats, the effects of human intervention, bin design and measures to be taken if rats are found in the bin as well as making the garden less rat friendly