Allyn River Permaculture

Permaculture demonstration farm in the Hunter Valley, NSW, Australia

Permaculture is a design system and philosophy that emulates the patterns in nature to holistically and sustainably integrate the physical and social needs of people and the ecosystem.


Composting  Workshop

Peter Brecknock – Allyn River Permaculture 

Composting is one of the best thing a gardener can do, it is the ultimate way of recycling, it nourishes plants including providing trace elements in a form instantly available to the plants.

Composting involves mixing garden and household organic waste in a pile or bin and providing conditions that encourage decomposition. The greater the diversity in the ingredients the better. The decomposition process is fuelled by millions of microscopic organisms (bacteria, fungi) that take up residence inside your compost pile, continuously devouring and recycling it to produce a rich organic fertilizer and valuable soil amendment

All you need to know about composting is a basic understanding of a few simple principles, and a little bit of effort. Nature does the rest.

Naturally, decomposition, or the composting process, occurs constantly and gradually around us every day. The dark, rich soil covering the forest floor is an excellent example of this. When we compost, all we’re really doing is speeding up Mother Nature.

Location & Receptacle
First you’ll need to select your location for composting. Where you put it depends on function and aesthetics. Don’t hide the bin away; it should be in a location that is easy to service.

Many of the new commercial compost makers are well designed, so they can be located closer to the house. There are many compost makers available, including tumblers or on ground units. We consider the conical bits that sit on the ground which allows access for worms and other beneficial insects, air slots can also be an aid for ventilation.

You can also skip the bin (a structure isn’t essential) and just have a compost pile or heap.

From a functional standpoint, you’ll need a place with good air circulation. Partial shade is a good idea so the compost doesn’t get overheated. Also make sure the spot of land where you place your heap gets good drainage.

Close to the garden and to a water source are both good places for building your compost pile since it will be easier to move the materials to and from the garden and easier to water it. Another idea may be to place it near your kitchen to make it convenient to place table scraps on the pile or in the bin.

A free standing compost heap should be about 1m3 in size. In fact, this is probably the perfect size. It’s sufficient enough to “cook” your waste and transform it into compost, but not so large that it will become unmanageable and hard to turn.

Ingredients – get the ratio right

The best compost is made from a diversity of materials. All organic matter is made up of substantial amounts of carbon (C)

combined with lesser amounts of nitrogen (N).

The balance of these two elements in an organism is called carbon-to-nitrogen ratio (C:N ratio).

For best performance, the compost pile, require the correct proportion of carbon for energy and nitrogen for protein

production. It has been determined that the fastest way to produce fertile, sweet-smelling compost is to maintain a C:N ratio somewhere around 25 to 30 parts carbon to 1 part nitrogen, or 25-30:1. If the C:N ratio is too high (excess carbon), decomposition slows down. If the C:N ratio is too low

(excess nitrogen) you will end up with a smelly pile.

Below are the average C:N ratios for some common organic materials found in the compost bin. For our purposes, the

materials containing high amounts of carbon are considered “browns,” and materials containing high amounts of nitrogen are considered “greens.”

Estimated Carbon-to-Nitrogen Ratios
Browns = High Carbon C:N
Ashes, wood 25:1
Cardboard, shredded 350:1
Corn stalks 75:1
Fruit waste 35:1
Leaves 60:1
Newspaper, shredded 175:1
Pine needles 80:1
Sawdust 325:1
Straw 75:1
Wood chips 400:1
Greens = High Nitrogen C:N
Clover 23:1
Coffee grounds 20:1
Food waste 20:1
Garden waste 30:1
Grass clippings 20:1
Hay 25:1
Manures 15:1
Seaweed 19:1
Vegetable scraps 25:1
Weeds 30:1

Note: Many ingredients used for composting do not have the ideal ratio of 25-30:1. As a result, most must be mixed to

create the perfect compost recipe. High C:N ratios may be lowered by adding grass clippings or manures. Low C:N ratios

may be raised by adding paper, dry leaves or wood chips.

Many home gardeners prefer to put up with a slight odour and keep some excess nitrogen in the pile, just to make sure

there is always enough around to keep the pile cooking.

Moisture – damp not wet
The compost pile require water for survival, but it can be hard to judge how much water to add and when. Too much water means your organic waste won’t decompose and you’ll get a slimy and smelly pile Too little water and you’ll kill the bacteria and you won’t get your compost

A rule of thumb: the more green material (cut grass, weeds, leaves) you put in, the less water you’ll need to add. In fact, if you need to add dry ingredients such as straw or hay, soak the material first in water so it won’t dry out your compost pile. In general your compost should be moist, but not sopping wet.

An easy test is to squeeze a handful of compost, it should feel like a wet spongy and you should be able to squeeze out one drop of water
It is also advisable to cover a compost heap so the water content can be controlled and not flooded by rain.
Aeration – get the air in
Oxygen is also required by many of the microorganisms responsible for successful composting. Give them adequate ventilation and they will take care of the rest, You can make sure that the bacteria in your compost gets sufficient air by turning the pile often and well. Use a pitch fork, spade or compost aerator to mix your pile. If you’ve got a compost tumbler, you’ve got it easy. Just crank that lever. Don’t aerate your compost and it will break down slowly, resulting in a slimy, dense, smelly pile. It’s also a good idea to turn the contents since it rearranges the decaying material. With a little care, you can move the less decomposed material on the edges to the middle of the pile to heat up.

Very nitrogen rich heap can reach temperatures over 70 degrees C, at this temperature the useful pathogens can be killed so the heap should be turned to remix the ingredients, aerate, watered if required which will reduce it temperature.

As the composting process takes place it generate large amounts of heat, which raise the temperature of the pile or compost bin and speeds up decomposition. A compost pile that is working well will produce temperatures of 50-65 degrees C at these temperatures almost all weed seeds and plant diseases are killed. A “very hot” compost pile will generate temperatures of up to 60 degrees C for three weeks or more. Use a compost thermometer to measure the exact temperature at different locations inside the pile.

When adding organic waste to your compost, don’t squash the materials down to make more space. Squashing the contents will squeeze out the air that the aerobic microbes need to (Instead you’ll be promoting the anaerobic microbes, which also do a good job converting carrot peels and other organic matter into compost but tend to be a lot smellier.)

Also be strategic about filling your bin. Include a mixture of brown fibrous ingredients and greens. A well-balanced “diet” will ensure that composting doesn’t take too long and that you don’t end up with a slimy, smelly heap. Also shred, dice or otherwise make scraps smaller, which will help the resident bacteria do a good job in converting the garbage into compost.

Finally, after you’ve added kitchen vegetable waste, throw some leaves or grass clippings on top of it. This will help keep things balanced, reduce smells and make your compost bin less attractive to critters who are trying to sniff out a free meal.

Composting  Problems       Q & A

Q: Help! I’ve created a stinky monster. Where have I gone wrong?

A: If your compost pile is smelly chances are it has an overabundance of anaerobic microbes. They’re doing a great job feasting on your garbage, but at the same time are creating a big stink. Usually, stirring and turning your compost pile regularly will put a stop to it.
Aerating the compost pile puts a check on the anaerobic microbes while encouraging the less smelly compost microorganisms to grow and prosper. Give it a try! You and your compost pile will be happier.

Q: I’ve noticed that my compost is damp and warm only in the center of the pile. What’s going on?
A: When it comes to composting, size does matter! Your pile is too small. Go out and collect some more composting materials and make sure to mix the new stuff with the old.
The ideal compost pile size should be in the range 1m3. Smaller piles can’t generate the heat necessary for plant material to decompose. Larger piles are harder to manage and may not decompose uniformly.

Q: Recently, while aerating my compost I noticed that the center of the pile was dry. How could that be?
A: Looks like you’re being skimpy with the water. Next time you aerate the pile make sure to water while turning the pile. Better yet, consider moving the pile next to your garden so when it gets watered… your compost does, too!

Q: I just noticed maggots in my compost pile. What’s the deal?
A: Some fly species lay eggs on decomposing plant material. Try adding a layer of hay to the pile and cover with hessian bag. However the maggots will not affect the compost

Q: What can I do in the dead of winter to keep my compost pile active?
A: The bacteria that work to break down organic garbage into compost do not do well in cold temperatures. One thing you can do to offset the cold is to keep your compost pile in a black bin in direct sunlight or you can insulate it using organic materials like hay bales.

Q: Arrgh! I don’t understand what’s going on. My pile is damp and has a pleasant smell… but it’s not heating up. What do you think the problem is?
A: Happy composting is all about balancing the brown stuff (carbon) with the green stuff (nitrogen). To keep your pile “cooking” you want to maintain a C:N ratio somewhere around 25 to 30 parts carbon to 1 part nitrogen. From your description, I’d say you’re running low on nitrogen. Try adding some fresh grass clippings, manure or blood meal. You can also “recharge” a cool pile with a compost activator. I bet you notice a big difference.

Q: What’s that ammonia smell?
A: Too much nitrogen. Add some high carbon materials, like straw, sawdust, or peanut shells to the pile and mix them in well.

Q: What can I do about shrinkage? My compost pile keeps getting smaller.
A: Shrinkage generally means low C content, the N component does reduce in size through microbial activity but as this is a relatively small proportion of the pile.

If this happens top up the pile with additional C material and mix well.

If using container bins it may be necessary to have multiple units to have a new one to fill while the other is cooking.