urg logo urg



Compost FAQ

This FAQ was compiled by Mike Loughlin. It is a distillation of comments from contributors to uk.rec.gardening

and was originally published on www.nugget.demon.co.uk.

Version 1.2 (1/4/96)


  1. What books/FAQs are there on compost?

  2. What's the secret?

  3. Should the sides be open?

  4. Do do do's and do do don'ts

    1. Can you put cat excrement on compost?

    2. ..and rabbit excrement?

    3. ...and elephant excrement?

  5. Can I put paper on the heap?

  6. Can one put cooked vegetable material into compost heaps?

  7. Should I put turf on the compost heap?

  8. Can I put woody material on the heap?

  9. Do bacteria die off once the compost is rotted?

  10. Where can I get cheap worms from in bulk?

  11. Leaf Mould

  12. Are tumblers any good?

  13. Can organic material be dug into the soil without first letting it rot?

1. What books/FAQs are there on compost?

Practically any general gardening techniques book will have information but there is also:

"Composting. The Organic Natural Way" by Dick Kitto

"The compost book" by David and Yvonne Taylor Published by Robert Hale, London @ about 5.99 ISTR ISBN 0 7090 5464 5
This is quite a good little book just about composting. The authors are Australian so the problem of composting in cold conditions isn't dealt with that well. It's available quite widely in the UK Waterstones, Dillons etc. or by mail order from the RHS at Wisley.[Paul Holman]

and on-line:
rec.gardening faqs [Steve Burley] (Good)

Compost [Dr. Andrew McCaddon] (Very Good)

VegSocUK [Andy Mabbett] (This page, aimed at vegetarians, has some advice on composting plus lots of other useful tips. Well worth a look)

2. What's the secret?

You HAVE to turn the compost once during its making - use two bins. Oh, yes - horse manure and gentlemen piddling on it make it go like the clappers!

I put everything on the heap - but try to layer things a bit if you can - coarse material in between finer stuff - paper mixed with grass - prunings (nothing too woody) - ALL kitchen waste - cooked and uncooked (vermin likely to go for cooked stuff will go for raw stuff as well, I reckon) tea bags, old spent pot plants and their compost, even old clothing if it is wool, silk (no, forget that - send the silk to me!!) or cotton, ripped up, though fabrics will take a while longer to rot down. The only things I avoid are milk products - they just seem to stink before they rot. Plenty of strawy horse manure if you can get it - and, dare I say again - Tiddle! - acts as an accelerator to get the whole heap heating up. Most important step after that is just to turn the heap half way through - about three months in my case or when the bin is full - then it will be aerated and off it will go again! [Roz Cawley]

If you prime the heap with nitrogenous material it goes a lot quicker (6-8 months) and runs much hotter internally. Ammonium sulphate or one of the proprietary compost accelerators will do if you are in a hurry. You still have to turn it occasionally though. [Martin Tom Brown]

Nettles make an excellent, (and cheap), accelerator for the heap. [Ron Lowe]

3. Should the sides be open ?

Not necessarily. I have used the same for many years, but use old gas pipe instead of 4" posts. As my heap is 4'x4' and between 2' and 5' high, it would not get enough air if the sides were solid. A smaller heap should probably have its sides solid.

4. Do do do's and do do don'ts

4.1 Can you put cat excrement on compost?

I don't think I would ever use cat/dog excreta on a compost heap - parasites and nasties, oh no. Well rotted horse manure is one thing, cat and dog muck quite another.[Dr David A Gladstone]

I would think when it comes to it that anything can be composted, given the right treatment and mix of ingredients. Obviously if the material isn't properly composted, then the result could be similar to just encouraging the cat to 'go' directly into the garden.[Clarke Brunt]

If you can get your compost up to a good temperature it seems to vanish, disgusting smell included. [Ian Luff]

All the authorities say: don't put pet waste in your compost. We do, with no ill effects whatsoever. The cats' used litter goes into the compost pile. I have difficulty understanding why any expert -- let alone all of them -- think this is a bad practice. [Peter Martin]

It's fine, but I would make two comments:
1) If you do this, it's probably best to wash all material you plan to eat raw (salads, fruit, etc.), very thoroughly to avoid transmitting
Toxoplasma - but don't get paranoid about this.
2) Put as little of the litter on the heap as possible - it turns into a sludgy mess. Hence you still have to dispose of the used litter somehow, so it is perhaps questionable whether it's worth the bother of composting what's left.[A.J.Cann]

Here in the US, we are strongly advised not to use cat faeces for fertiliser, either as compost or directly. Apparently most cats here carry something called toxoplasmosis, which can be seriously detrimental to developing foetuses. People who normally live with cats have been exposed, and may even have had a slight case of it, without knowing since it resembles an ordinary cold/flu. Any immunity acquired though is apparently not passed on to the developing child. In fact, pregnant women are advised to avoid cleaning the litter box. Maybe a vet or a paediatrician would be able to tell you whether cats in the UK carry the same disease? [Jacque Greenleaf]

4.2 ..and rabbit excrement?

Yes. We do that with guinea pigs. My belief is that the common UK animals whose faeces and urine are most likely to carry dangerous diseases are cats, dogs, rats and possibly pigs. If anyone has the facts at their fingertips, I should be interested in any more precise information. It is very important to ensure that any solid lumps of paper are removed or shredded and the bedding gets properly damp. [Nick Maclaren]

It should work great on your compost heap. Get as much as you can but mix it up well with other stuff. [Kevin Pyke]

4.3 ..and elephant excrement?

I kid you not! Geoff Hamilton in his "Successful Organic Gardening" recommends getting in touch with the circus when it comes to town. They will probably give you a couple of truck loads of the stuff.

5. Can I put paper on the heap?

Wonderful stuff on a compost heap - paper - don't use too much at once. We use mainly newspapers here, I must admit - the boys tear them into about one inch strips, then mix them in with grass cuttings when Alec (Dad) cuts the lawn. Oh, yes - don't forget to pee on them afterwards - brilliant compost will instantly be yours! (Well, in six months, anyway - almost instant in gardening terms!) [Roz Cawley]

I've used the stuff that came from the works document shredder with some success (mixed with at least the same volume again of leaves/grass/etc.) and well watered. [George Poulson]

I doubt that black ink will be a problem, because it is usually mainly carbon, though I am much less certain about coloured inks and the toner. Glossy magazines etc. are definitely not a good idea. While I have had success with paper, I find it too much hassle and rarely bother (but I don't separate it out, either). The usual reason for the failure of paper to compost is that it is put on the heap still folded, which prevents air getting to it (even when it gets wet, which isn't always). As it is fungi that break down wood and paper in a normal compost heap, and they need air, nothing happens :-( So it is BETTER to use shredded paper (if the toner isn't a problem). Fungi also need a source of nitrogen (cue the 'peeing' thread!), so a handful of general-purpose fertiliser is a good idea. The usual problem with lawn mowings is that they compact, and form silage (again, anaerobic), so they need turning or breaking up. Long grass isn't usually a problem, unless the heap is very dry, but can be slightly woody (and so needs air and time for the fungi to break it up). My guess is that long, dry grass is better composted using a traditional heap than a bin or tumbler. [Nick Maclaren]

No problem with newsprint (without metallic inks) or similar material like paper towels etc. The better shredded, the faster the decomposition. I don't think paper provides much "value added" in our compost, but it's certainly more useful on our gardens than in a municipal dumpsite. [Peter Martin]

6.Can one put cooked vegetable material into compost heaps?

It's fine unless you use a great deal of cooked material. Kitchen scraps are fine, along with uncooked material as well.[Marjorie Rosen]

I put in anything organic, cooked or uncooked, and have had no problems over the last two years producing super compost. In the summer a rat did decide to take up temporary residence but soon shot off when I turned the heap over and hasn't been back since. I think it was the large amount of straw bedding material from the children's rabbit that attracted it rather than the food scraps. Aeration would seem to be the key to good composting and a regular turning over does wonders! [Phil Whitehead]


I read that turves should be stacked, face down, then covered with polythene, carpet or such like. After a year(or two?), you should have a dry loam which can be sieved before being used as a soil improver or added to leafmould etc. for use as a potting compost. At least I hope so, 'cos I've got a ton of the stuff in my garden at the moment! [Andy Mabbett]

8. Can I put woody material on the heap?

Semi-woody stems etc. are IMMENSELY useful in ordinary compost for either a clayey or sandy soil. They rapidly break down into a coarse fibre, which is excellent for aerating clay and holding water in sand. But you do need to use the traditional method of composting for this to work easily. If you use 6-week tiger worms or some such method, start a separate heap for semi-woody waste. Incidentally, even 1/2" privet clippings will break down within a year or two using this method, but you MUST keep the heap aerated, damp and provide some nitrogen (e.g. kitchen waste or even general-purpose fertiliser). [Nick Maclaren]

One tip I read recently, for those of us who don't have a shredder, is to place woody (and especially "half-woody", such as sunflower) stems on concrete and "tenderise" them with a hammer.[Andy Mabbett]

9.Do bacteria die off once the compost is rotted?

Most bacteria will do what you say, including the most common bacterium in human waste (Escherichia coli (Genetics, Goodenough & Levine, ISBN 003 910174 6, p870) [Stewart Robert Hinsley]) Some will stay dormant for a long time, and others will form very resistant spores (such as Anthrax and Tetanus). The same thing is true of other micro-organisms (such as worms, fungi etc.), but the dormant form may be eggs, cysts or whatever. Most viruses cannot live for long outside living cells, but a few seem to survive for relatively long periods. For example, I believe that you need not worry about getting polio from compost heaps, despite the fact that UK sewage (such as fills our rivers and coastal waters) is riddled with it. The main causes for concern are parasites that both have a long-lived, resistant form and can cross-infect humans from domestic animals. There are not actually very many of these, which is fortunate. [Nick Maclaren]

10. Where can I get cheap worms from in bulk?

Try going to a fishing bait supplier and getting some "brandlings"? (Your local fishing tackle shop will normally stock them). You don't need many as they will soon breed and increase in number. I bought half a pint for an average domestic sized dustbin and this was more than enough. Each time I emptied the bin I kept some of the compost (and worms) as a starter for the next bin. [Steve Jennings]

11. Leaf Mould

I would appreciate any advice on how to make good leaf mould (beech, maple, chestnut). I am about to try mixing grass cuttings to try to accelerate decomposition and provide missing nitrogen. [Kevin Parrott]

According to the RHS "Organic Gardening" book in it is recommended that the addition of some grass cutting will hasten decomposition. Chopping up the leaves also helps so picking up leaves with a lawn mower is an efficient method in more than one regard. Urine also helps but perhaps this should be supplied after dark or the neighbours might think it some sort of male territorial thing! [Mike L]

Monty Don is very keen on leaf mould and says to keep the pile of leaves wet. This is presumably only needed during the summer. Then the pile breaks down in a year or so instead of the usual 18-24 months. [Des Higgins]

Spinkle some ammonium sulphate onto the leaves as you make the heap. This will provide the extra nitrogen to speed up composting. You may have to turn the heap as the leaves tend to compact down. [John Fox]

12. Are tumblers any good?

I'd say they are good, but haven't been able to give them a fair trial as yet. The makers say that you can have compost ready in 3 weeks, which may be true in the summer months when temperatures are higher. Composting seems to take slightly longer in the autumn/winter, but seems to be progressing far faster than my usual heap, and is a lot less smelly! The autumn leaves I collected and threw in there are well on their way to being broken down, also thanks to the remarkable effects of urine on the heap, and thanks to a good soaking and scrunching up in water prior to adding to the tumbler. I'll let you know in the spring/early summer, how much faster composting takes place. Has anyone else out there used a tumbler? [Dr. Andrew McCaddon]

13.Can organic material be dug into the soil without first letting it rot?

I can remember an article in Gardeners World in which it was advocated that if you had very thick clay soil it could be improved by digging in straw, the rational being that as the straw broke down it left channels in the thick clay improving drainage and organic content at the same time. Contrary to popular belief, no nitrogen shortage was found. The soil bacteria converted inorganic nitrogen into cell protein during the decomposition of the straw which was released back into the soil as they subsequently died. [Phil Whitehead]

However, I would qualify this by pointing out that clay soil is probably very fertile so nitrogen deficiency probably wouldn't be a problem anyway. The improvement in soil condition alone justifies digging in straw.[Mike L]

Similar remarks apply to sandy soil, because it improves water retention, but you do have to watch out for the lack of nitrogen. What I do is to compost both kitchen waste and semi-woody or woody material, and dig the stuff in when the latter has started to break up. When I have dug up vegetables, I have often found that their roots are thickest in the half-rotted fibrous material. But remember that sandy soil in Cambridgeshire almost classifies as semi-desert :-) [Nick Maclaren]

Page hosted by © cormaic web design, 2009