Gardening & Wildlife


Worm bins are a great idea. I personally have two in my conservatory for which isn't enough to take the waste of a single person living alone. Hence, worm composting should be supplementary to your bog standard type composting in the back of the garden. There are some very important rules one should remember about worm composting though. Firstly, treat your worms like pets, even if you use them as fishing bait. Secondly, they work on very different principles to either aerobic or anaerobic composting in which bacterium and fungi degrade the material into various minerals and compounds whilst at the same time giving off heat. Worm composting is another way of collecting manure commonly known as worm casts (there is something about their sacrificial nature prevalent throughout this text) and could be likened to chickens; one feeds them fresh kitchen waste and waits for them to shit. Like poultry manure it is very powerful stuff and must be mixed at least in equal parts to spent soil. The method I am going to show you here is very quick and easy to achieve and ensures that the worms have optimum living conditions. What's also important to know is that they don't like it too hot/cold or wet. Our first step regards the bin to use. Make sure it has a good fitting lid, ideally a lid with a lip around its entire edge. This become apparent when the bins are close to full and opening the lid exposes thousands upon thousands of worms entwined in some crazy mating ritual, spilling out all over the floor. It is a sight to see. Black bins tend to get too hot, whilst odd shaped bins may be difficult too seal. Go for a perfectly round green or brown bin, even a square one, not like the one I am showing you here. Clean it out and drill an area the size of a large margarine tub with equally spaced 4mm holes. This is so that it collects all excess fluid commonly known as worm pee. Notice here too that I am drilling air holes about a quarter and half way up around the circumference of the bin. Again, equally space them out.


Next, place a 10cm layer of shingle in the bottom of the bin as drainage, much as you would do with a large plant pot. The stones also assist in the build up of humidity, which the worms like. Since the drainage is at the bottom the continue depletion of fluid tends to negate this effect. A more advanced system could locate an operable drainage tap further up the bin side. Next, place a partition over the levelled out shingle. Notice here that the ply has been covered in a plastic to prevent the worms from eating it. It also inhibits rotting, which is expected to occur to a degree. You have to drill holes through this also unless the moisture can escape through the sides, as in the case of my bin it can. Better still, use a plastic barrier instead. I have never tried metal, which could work since as far as I know worms hate metal.


Place a layer of starter material in the bottom, at least 10 cms thick, with a good handful of worms in it to get the process going. You can find this rough material on the edges of a standard compost heap. Undoubtedly it will contains slug eggs and other fauna, but this is fine if you don't mind opening the lid one day and seeing the most enormous slugs ever. I suppose it is better than meeting a rat. Anyhow, they will find their way in somehow, maybe from garden waste added to it. Subsequent material can be saved from the tops of full bins that need emptying.


Locate your bin near to the kitchen, ideally next to the back door. I have heard of a person having it in the kitchen with a chopping board over the top. From experience I know that every bin attracts fruit flies, and they also breed prolifically when the weather warms up. Without doubt to have a door between the kitchen and the worm bins is a must-do. Now raise the bin on bricks so that a collection tub can be located underneath it directly below the drainage holes. It should be easily removable, as should the lid. At this point one adds a little kitchen waste and waits for two or three weeks. This allows the worms to settle in and get used to their new environment. Now something should be said as to what you feed them, and how. Firstly, they eat fresh food, not rotten stuff; they are animals like all of us. They love a vegetarian diet but if you have surplus meat they will go for that also. The risk here is that you attract flies or rats when the meat starts to rot. What's important is a good variety, finely cut so that they eat it before it begins to rot. Personally, I don't bother though. Secondly, worms also consume carbon, which is why I also chuck my egg boxes inside. They get through the stuff quite quickly once the breeding program is ongoing. I have tried old socks and boots but amazingly rediscovered them at the bottom of the bin with all their synthetic materials remaining; they just don't like nylon, and that goes for my pants as well (although I always give them a wash before I use them for rags). Also, too many egg shells are unsightly. Even though the worms partially break them down and the calcium 'sweetens' the soil, the sheer number we eat leaves a rather good free-draining compost, which when added to other soil makes their presence negligible. Keeping the soil from becoming too acidic or alkaline requires avoiding too much citrus. Likewise, a sprinkling of calcified seaweed or hydrated lime applied every 15cm will 'sweeten' the soil. As well as this throw in a few plant roots as this will contain the grit required for their digestive systems. And lastly, don't overfeed them; they become complacent otherwise. It is best to keep them a little hungry. If you have too much waste then compost it using another method. And remember also, it will take up to a month to get them going, and only in mild weather.


The type of worm is important. Commonly known as Tiger worms (Eisenia foetida), they should not be mistaken for earthworms, which burrow down and pull material below the surface. Tiger worms live in the top 15cm of the soil. Each adult produces 2 to 5 cocoons a week, each containing 10-15 hatchings which themselves mature in seven to eight weeks. In warm weather they appear after three weeks as tiny threads. Worms will die if the food source runs out. They will also stop operations and rest below 8 or above 25 degrees C. They work best between 13 and 25 degrees C. and should be kept inside during winter, or insulated. To give you an idea on how prolific they are, under the right conditions 1 acre = 8.000,000 worms and one worm can ingest 4.5kg (10lb) of soil a year.

Further Pages

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Abstracts & Reports

  • Green Roofs
  • Greenhouse Rotation
  • OTHAS bird report 2005
  • Pest & Diseases
  • Composting
  • Grafting & Budding
  • Gray Water Use in the Landscape
  • Loss of Birds from our Habitats
  • Nut Production in the UK
  • Pruning
  • Rotation1
  • Rotation2
  • Soils
  • Three 6 yr Rotation Plots
  • Wild & Soft Fruit Selection1
  • Wild & Soft Fruit Selection2
  • Wild Edible Foods
  • OTHAS Orchard Proposal
  • Woodland Management
  • Willow - Salix
  • 6.

    Other than the final product of manure it becomes apparent that the bin produces another kind of fertiliser. That is worm pee. This liquid is a combination of natural juices draining from food particles plus the secretions of soil fauna. The colour is of weak urine. It has various applications. Mixed 1:10 with water it can be applied to plants during the growing season. I personally tip the contents of the collection tub straight into the rain butt without any inclination to moderate the ratios. Worm pee is not compost tea. There is evidence to suggest that it does more harm than good to one's plants and that it is better applied straight to a compost heap as an activator. Bearing that in mind it may be better locating the bins above soil and planting up the immediate area with comfrey, a superb mineral accumulator. This can then be regularly cut and used for composting.


    After 6 to 12 months the bin will have filled up. There will be a grade of different material from top to bottom. On the top is the fresh kitchen waste. A few centimetres down, where most of the worms are, the material will have gone to a rought texture of mostly a black colour. This stuff is still being consumed but should also be skimmed away to start the next batch in an empty bin. Further below this is a compressed material made of worm casts. This will be slightly moist and is best left to dry out separately. The issue is: how to divide the material whilst collecting most of the worms? The answer is quite simple. Remove as much of the top material as you can with a scoop and put to one side. This is easily done. Most of the worms will be here. Lay a sheet about 10' by 10' and invert the bin into the center of it trying as hard as possible to prevent the partition and shingle from dropping out. Remove as much of the fertiliser material as you can get. As for the worms they will always locate to the middle away from the edges since that is where they are most exposed. Just biding a little time will allow you to perioically pull away all the outside material whilst leaving most of the worms behind. You need not be too fussy here. Seal up the good stuff in an aerated container like a fine mesh bag and leave to dry out. Start a new bin with what remains.


    The usuable material wil eventually feel crumbly and is very workable as a mixer. The quality of the soil can not be underestimated. A worm cast can contain five times more nitrogen, seven times more available phosphates, eleven times more potash and forty times more humus than is found in the top 15cm of soil where they live. Not only that, they harbour beneficial microorganisms that condition the soil where they live.


    As I say, one bin is not enough as it soon fills up. They take up very little room in the garden or conservatory and look tidy. Modern, household version that can be purchased in the shops don't do the job any better. They cost alot, look nice, but produce no way the same amounts. Instead, get yourself a nice looking bin. I recently found a big round, yellow one with a bright red lid. You will eventually get through the squeamish stage, and just fiddling around the top of the bin uncovers the most amazing soil fauna you can imagine. One for the kids!

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