Making Compost - part 2

In this second blog post on making compost we look at what people make compost in, and tools and gadgets that can be useful when making compost.

'luxury' compost bays at the Botanical Gardens in Hobart

The ideal spot for a compost heap ....

• Is level and there is good drainage below the compost heap, so excess water can drain away. For this reason a concrete slab or paved area does not make a good base for a compost heap. They also don't provide ready access for worms that may wish to help the composting process.
• Is shady, so your compost heap does not dry out. The shady side of a building or wall is ideal. Don't put it in the shade of a nearby tree because the tree roots will happily invade the compost heap and take a lot of nutrients.
• Is near a source of water
• Is near where most garden waste is collected
• Is in an area that is allowed to be less than spotless because composting is messy

The simplest compost heap structure is no structure at all

Just select a flat non-sloping area out of the sun and build a compost heap without anything around it to contain it.  Air is one of the key ingredients for making compost, so this type of compost heap has the advantage that air can readily access the heap from all sides. 

Having no walls for a heap works fine, but because nothing confines the heap to a specific spot, inevitably the heap will have a bigger foot print.  The no-walls method is for large heaps on properties/farms where there is plenty of space.  In my garden I would not have the space to have two heaps without any structure next to each other.

Using mesh and a pallet

At the end of one of our past Food Garden Group winter-workshops presenter Letetia showed us her very simple but effective compost heap structure: a circle of mesh held together by two bungee cords on weed-mat, on top of a pallet. The weed-mat lets surplus water escape onto the ground below.

The advantage of using this type of structure is that it is cheap, easy to construct and the next heap can be made somewhere else in your garden. 

Remember we talked about the ratio greens/browns in Making Compost - part 1?  For compost that is meant for veggie gardens it should be around 50:50. Letetia (on the left in the photo below) used the small squares of mesh to easily measure out that ratio. She put into the circle 'three rows-of-mesh-worth' of browns, made the material wet, then added three rows of greens, made them wet, then added three more rows of browns, and so on. Letetia used the circle on the left pallet to measure it all out, then she transferred the whole lot to a second circle of mesh on the pallet to the right. In the process of transferring, the browns and greens were mixed.

The purpose of the pallets is to allow excess water to escape and air to access the heap from all directions, even from below.

Compost bays

Compost bays are a good way to confine the size of a heap and, some people argue, they also better protect agains heat loss. 

After Loes moved into her new property at Conningham she soon had a large amount of garden waste and no compost bays to put it in, so she quickly made compost bays from sheets of galvanised iron:

She is still very happy with her compost bays, but wants to replace the front panels with planks, so taking material in and out will be easier (see also further below).

Lian at Lauderdale made a great looking compost bay out of pallets (photo below).  The right-hand panel opens out. Lian reported that her chooks hop in and out of the bin whenever they feel like it and help aerate the compost. After a while she shifts the compost into a second bin which is covered, so chooks can't get in, and worms then get a chance to thrive.

Pallets make great compost-bay walls because they are pre-made, so they save a lot of work, are cheap or free, allow air in for ventilation, and are a great way to re-use otherwise discarded timber.

Serena and Richard at Lauderdale used pallets to make three bays. Each bay is approximately 1.2 by 1.2 metres wide:

As a heap becomes higher you add more planks at the front.  This means that you never have to lift things higher than necessary when putting them in the bay, and you can take out all the planks when emptying a bay.

If you decide to position a compost heap in the shade of trees, make sure that trees roots can not reach your compost heap, because a tree will very happily invade your compost area and take a lot of nutrients out of your compost.

Above is another good example. This tidy arrangement of two bays does not take up a lot of space, and produces heaps of compost. A coil of mesh in the middle adds air to the middle of the heaps.

Clodagh's compost bays at Lindisfarne have solid fronts which means you don't have to lift out individual planks.

I found a 'Rolls Royce' of compost bays near the veggie patch at the Botanical Gardens in Hobart.  Tino Carnevale explained that he has three bays because he collects materials in one, active composting is taking place in a second bay, and the heap in the third bay is ready for use.

The bays are made out of beautiful hardwood railway sleepers.  I lifted one of the front logs out, so you could see the top of the heap in the middle bay.  The log was very heavy.  I would have preferred a front made out of thinner lighter planks.

The advantage of a structure like the one in the Botanical Gardens is that it would not be hard to make it vermin-proof (by adding lids with mesh).  Without holes in any of the walls that allow in air, you would have to turn over these heaps regularly to aid the composting process.

Plastic compost bins

The photo below shows a traditional plastic compost bin with a lid.

For those who think that all you have to do is gradually fill the bin, and compost will magically materialise, this system will be a disappointment, because it is difficult to control moisture and air levels further down the bin. The result is often stinky anaerobic compost that has no value to the food garden at all.

Food Garden Group members who like these bins tell me that a compost aerator (photo below) makes aerating further down their bin a lot easier.

It is important not to install this type of bin in a sunny spot as it can get too hot inside. 

The bin in the photo above was put on concrete (does not provide good drainage) on the shady side of a house (great!).  I recommend that you rest your compost bin on soil, so excess water can drain away. It will also allow worms to join the bin from below.

Before filling your compost bin, dig a shallow hole slightly larger than the diameter of the bin, in the ground where you are thinking of putting the bin.  Fill this hole with water and find out whether it easily drains away. If it does, it means that excess water in the bin will have a good chance of being able to escape the bin.  If the water does not drain away within a few minutes, find a better spot.

Put the empty bin in the hole! By putting the bottom of the bin a bit below the level of the surrounding soil, and then surrounding it with some of the soil that you dug out, you may have made an enclosure  that vermin will not easily be able to enter from below. 

If you are not concerned about local vermin entering your bin, put the lid only loosely on the bin, so air can enter the bin from above.

I would recommend that you buy a compost aerator and use it as often as possible. Never compress materials that you put in the bin, so you don't squeeze all the air out of the bin. 

Compost tumblers

I like compost tumblers much better than plastic compost bins. They are very effective in the production of small quantities of compost.

The tumblers shown in the photos below can be rotated around a horizontal axis and you have easy access to the whole content of the bin via a lid. 

The handle allows you to rotate the tumbler by hand. The purpose of rotating is to (re)mix materials and add air, so its purpose is the same as turning over a heap. When there is a lot of stuff in the tumbler, rotating is obviously harder, so it is best not to overload it, although turning a full tumbler is probably less work than turning a traditional compost heap.

 

An important advantage of a tumbler for people who have a vermin problem is that rodents can not access your compost. For an expert's use of a compost tumbler see 'How Wendy uses her shredder and tumbler' below.

Another creative solution

Things don't have to look professional or be sophisticated to work.  Wendy in Sandy Bay (who makes great compost) has a number of enormous boulders in her garden and she uses them as borders for her compost making area.

Shredders

A shredder (see photo below) can be a great tool to efficiently turn large quantities of garden waste into mulch or compost. A stalk cut in many small pieces will turn into compost much more rapidly and easily than a stalk cut in only a few pieces by hand, so if you regularly have a lot of garden waste of this nature consider a shredder to make compost or mulch.

There are some choices to be made.  An electric shredder may cost under $500, is not very noisy, needs a powerpoint nearby and is for less demanding jobs.  A petrol shredder ($1000 - $2000) can be taken to wherever the job is, is more powerful, but more noisy.

I had a reasonably powerful petrol shredder some decades ago and learnt that the faster you get to know the limitations of your shredder, the better friends you are going to be with it.  Dry materials that are too stringy or sodden grass clippings or branches that are too thick can bring your shredder to a halt and some people spend more time unclogging than shredding. Learn to respect the limitations of your shredder and it will do a great job for you.

Alternatively, you can simply shred your garden waste with a lawn mower. It can work a treat, if, once again you realise the limitations of your equipment! If you don't want to spend money on a shredder/mulcher, consider using your lawn mower for shredding of non-stringy, non-woody garden waste.

A great use of shredder, sieve and tumbler

By suburban standards Wendy in Sandy Bay has a large ornamental and veggie garden. She shreds garden waste regularly, soon after removing it from the garden, so it does not dry out and become too stringy.

Wendy then takes the resulting shredded material and sifts it with her home-made sieve (see photo below), an old table frame on top of which she put stiff mesh and then finer mesh on top of that.  Notice the great use of a just-the-right size toddlers peddle pool underneath. The black stuff in the photo is coffee grinds that also are put through the sieve.

Wendy puts material that stays on top after sifting on her normal cold-compost heap. Materials that do go through the sieve are composted in her large tumbler together with already partially composted stuff from her cold-compost heap and fine drier materials that are added to make sure the mix is not too wet.  With this mix she turns a tumbler full of material into compost in only a fortnight (at any time of the year except winter).  That is fast.

Wendy recommends that you ...

• Rotate your tumbler every few days to add air to the process and avoid compacting.
• Don't go above the bottom of the lid when filling up the drum
• Use only fine materials and finely shred or cut materials
• Monitor moisture levels as surplus water can not escape

May your compost be rich .....

Max Bee
(with many thanks to Food Garden Group members who contributed photos and info to this post)