Composting - Actsmart.act.gov.au

Compost
Compost is a fantastic and free soil improver. It
reduces household waste by converting your
organic kitchen and garden waste into wonderful
nutrient rich material for your garden.
Compost is a living system. It is full of good
bacteria, microbes, worms and other creatures.
They are all important for creating healthy soil. All
living things need air and water to survive and so
your compost should be kept moist and turned
regularly to let air in. Airflow will also prevent your
compost from smelling bad. Your compost is ready
to use when it looks and smells like soil.
CHOOSE THE TYPE OF COMPOSTING THAT BEST
SUITS YOUR SITUATION
Direct composting
You can bury vegetable matter in holes in the ground.
Deeper than 10 cm will help to keep the flies at bay
but if you have dogs you may need to go much
deeper. Compost can generate a lot of heat so create
small piles away from young root systems.
Compost bins
This is often a slower process as the heat doesn’t build
to the necessary temperatures and the whole process
may take 12 months or longer. Because of this most
households need 2-3 bins, one you are filling and one
ready to harvest. Compost bins work best if in contact
with the ground so that worms can escape the heat
generated by the bin. Ideally turn the compost at
least once a week but this can be difficult to do in a
confined space.
Compost tumblers
Worm farms
Designed to be turned at least once a day these
can be a much faster way of composting if used
correctly. Add manures or compost to the mix
as you won’t have worms or microbes from the
surrounds like you do when the compost is on
the ground. You may find it easier to compost in
batches as it’s difficult to separate out the old from
the new compost in a tumbler.
A great way to involve the kids, worm farms can be
a fast and easy way to turn vegetable scraps into
fantastic soil. Make sure the worms can retreat into an
area away from their food and don’t over feed them
especially when starting out. If you can smell the food
rotting remove some until the worm population can
build up enough numbers to keep up with you. Avoid
too much citrus, onions, pineapple and try to cut larger
chunks up to help them out. Keep the worm farm
damp but not wet, out of the hot sun and feed them
weekly to keep them happy.
Compost heaps
You can construct a heap out of timber slats or
wire or just have a heap on the ground. Aim for
at least a square metre in the sun with good
ventilation away from the house. You may need
to cover the heap with hessian or construct a lid
to keep the heat and moisture in. For best results
turn the heap once a week and keep moist but not
soaking.
WHAT CAN I ADD TO MY COMPOST?
Kitchen scraps, tea bags, coffee grinds, paper (not
glossy), shredded cardboard, prunings, leaves,
lawn clippings, old cut flowers, egg shells, lint, pet
hair, animal manures (but not pet manures), straw,
sawdust and much more. Anything that is dry
should be soaked before adding.
WHAT CAN’T I ADD TO MY COMPOST?
Meat, bread, fish and dairy products are likely to
attract rodents. Oils and fats are difficult to break
down. Cat or dog manures can invite harmful
bacteria. Do not add noxious weeds like ivy and
privet or any diseased plants. If your compost is
not hot enough the diseases and the weed seeds
may survive the composting process and be
spread around your garden with the compost.
Composting is a completely natural process and
creating a compost heap couldn’t be easier, but
if you are impatient there are things you can do
to speed up the process. Heat, aeration, moisture
and the right size and ratio of ingredients are key:
•
Place the compost heap in the sun
•
Keep the compost moist but not soaking wet
•
Layer the materials
•
Add manures
•
Turn the heap if the temperature has dropped
•
Larger heaps (1m3+) will generate more heat
•
Keep the carbon to nitrogen ratio close to 30:1
A BALANCING ACT (The carbon to nitrogen
ratio)
Organisms that decompose organic matter use
carbon as a source of energy and nitrogen for
building cell structure. They need more carbon
than nitrogen. Decomposition of organic
materials in your compost pile is greatly increased
when you create the proper balance between
carbonaceous materials (called BROWN because
they are dry) and the nitrogen rich materials
(called GREEN because they are more fresh and
moist). Add a combination of materials to keep
the ratio as close to 30 parts carbon (C) to 1 part
nitrogen (N) as possible - this is the fastest way to
produce fertile, sweet-smelling compost. 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 stinky compost.
If the above seems too confusing an easier
strategy is to mix your compostable materials
using two parts green to one part brown.
Generally speaking you can get C:N ratios of 30:1
to 50:1 by adding two parts of a green material to
one part of a brown material to your compost bin.
A ‘part’ can be defined as a certain quantity of the
material such as two 9 litre buckets of green and
one firmly packed bucket of brown.
Play with the table below:
For example, food scraps, lawn clippings and
leaves come close to an average of 30:1. How?
Add up the carbon side of the ratio for all three
materials, i.e. 15+20+60, and divide by the number
of materials, i.e. 95/3 = about 32:1.
COMMON COMPOSTABLE MATERIALS AND THEIR CARBON:NITROGEN RATIO (C:N)
Greens – High Nitrogen
Browns - High Carbon
Food scraps 15:1
Leaves 60-80:1
Animal manures (such as cow and sheep) 20:1
Straw 90:1
Chicken manure 7:1
Sawdust, cardboard (shredded) 350:1
Lawn clippings 20:1
Paper (shredded) 175:1
Coffee grounds 25:1
Nut shells 35:1
Humus (soil) 10:1
Pine needles 80:1 (can be acidic use sparingly)
Fruit waste 25:1
Wood ash 25:1
TRIED-AND-TRUE COMPOST RECIPES
1. Four parts kitchen scraps (fruit and vegetable),
two parts chicken or cow manure, one part
shredded newspaper and one part shredded
dry leaves.
2. Two parts kitchen scraps, one part chicken
manure and one part shredded leaves.
•
Keep your compost moist to prevent airborne
spores or bacteria being inhaled
•
Avoid working with your compost in a confined
space
•
Consider wearing a face mask if known to be
susceptible to allergies, asthma or other respiratory
problems
3. Two parts grass clippings, one part chicken
manure and one part shredded leaves.
HEALTH AND SAFETY
On rare occasions, illness and allergies can occur
from exposure to the living organisms in compost.
For health reasons we recommend you take the
following precautions when handling and working
with your compost.
•
Always wear gloves
•
Wash your hands thoroughly after handling
compost or soil materials
MORE INFORMATION
www.abc.net.au/gardening/factsheets/
For more information on sustainable programs
available in the ACT
Website: www.actsmart.act.gov.au
Phone: 13 22 81
Email: [email protected]
TROUBLESHOOTING YOUR COMPOST PROBLEMS
SYMPTOM
CAUSE
SOLUTION
Compost pile is wet and smells
like rotten eggs.
Your pile is too wet and there
is not enough oxygen.
Turn your pile to aerate it and add dry
carbon (BROWN) materials to absorb
excessive moisture.
Compost pile is not heating up.
Not enough nitrogen (GREEN).
Make sure you have enough nitrogen
rich sources like manure, grass
clippings or food scraps.
Mix up the pile so it can breathe.
Mix up the pile and add water to
moisten.
Wait for Spring, cover the pile or use a
compost bin.
Not enough oxygen.
Not enough moisture.
Cold weather.
Matted leaves or grass
clippings aren’t decomposing.
Poor aeration or lack of moisture.
Avoid thick layers of just one material.
Too much of something like leaves or
paper won’t break down well. Break
up the layers and mix well.
Attracts rodents, flies or other
animals.
Meat and other animal products
have been included or the
food scraps are too close to the
surface of the pile.
Don’t add inappropriate materials
to the compost. Bury kitchen scraps
near the centre of the pile.
Ants
Your pile could be too dry or has
too much BROWN material.
Mix up the pile and add water to
moisten. The ants will soon leave.
F00553 - T
Printed on recycled paper Dec 2012