This document provides information on companion planting and composting. It discusses how certain plants support each other when grown together, forming cooperative groups called guilds. It also explains the benefits plants can provide when grown with other plants or animals, such as improving soil conditions, providing shelter, and hosting predators. The document then covers the basics of composting, including suitable materials, constructing a compost pile, and signs that compost is ready. Tips are also provided, such as how to compost diseased plants, perennial weeds, and different garden wastes.
1. Companion Planting and Composting, Hollard Gardens, 27 September 2009
Home Garden Workshop 5 – Companion Planting and Composting
‘Guild’ is the permaculture word for co-operative groups of plants and animals that support each other and
thrive when grown together. Usually, they have evolved in the same place and under the same conditions. For
example, beans, corn and pumpkins support each other (in South America they call them the ‘3 Sisters’). They
occur naturally and also in wild systems. Acacias and eucalypts grow well together; legume and cabbage
families help each other thrive.
So, guild plant or animal species are strategically selected to boost the productivity of the central animal or
plant element. The central element can be a fruit tree, for example. The guild members then, must either
improve its yield or reduce the work needed to manage it.
By design, this enhances the overall self sufficiency and sustainability of the system.
The range of benefits that can be derived from guild species include:
• Providing mulch:
Plants that either act as a living mulch (e.g. nasturtium and borage) or shed mulch onto the soil (e.g. banana
grass, poplar) form a protective cover over soil thereby improving soil conditions and retaining moisture.
• Offering shelter and protection from frost, wind or sun:
Hardy nitrogen-fixing “nurse” species (e.g. honey locust, acacia, tagasaste) interplanted with orchard trees can
moderate frost effects, give nutrition to soils, and provide mulch and shading for sensitive fruit trees such as
avocado and citrus.
Others planted as a windbreak bordering orchards (e.g. cane grasses, poplar, casuarina) can be used to
deflect or diminish frost and drying or damaging winds.
• Hosting predators:
Many predators of garden pests (e.g. wasps) only hunt to feed their offspring, themselves being wholly nectar
feeders. Providing forage for adult stages is thus part of companion planting for a bug free garden (most small
flowered plants provide this, especially umbelliferous plants. Almost every widely cultivated plant of the
Apiaceae or Umbelliferae family (both names are used) is a companion plant. In large part, this is because the
tiny flowers forming the umbels, for which the group is named, are perfectly suited for parasitic wasps and
predatory flies, which actually drink nectar when not reproducing. They then will prey upon insect pests on
nearby plants. Some of the plants, too, are herbs that produce enough scent to possibly dilute the odors of
nearby plants, or the pheromones or emitted by insects that find those plants, which would otherwise attract
more pests.
• Remove pest habitat:
Larval forms of orchard pests such as fruit fly flourish and multiply in fallen fruit, so seasonally introducing a
forager such as pigs or poultry aids in pest control while adding fertilizer (and tilth if left too long) to soil.
• Prey on or deter pests:
Insect eating birds (e.g. honey-eaters) can be encouraged by planting a few nectar producing and insect
hosting plants (e.g. buddleia, banksias, dryandras, fuschias, callistemon, salvia) scattered around your orchard
and vegetable growing zones.
Most duck breeds (not muscovy) will clean up slugs and snails and can be ranged through your food
producing areas periodically when their appetite for seedlings will not compromise your yield.
• Killing root parasites or pests:
For example, Tagetes marigolds fumigate soils against nematodes and grasses, while Crotalaria (Australian
Bird Plant) disables nematodes that damage citrus and solanum plants (e.g. potato, tomato, eggplant,
capsicum).
• Providing nutrients:
Nutrient enhancing plants can be allowed to grow then slashed periodically to provide mulch (e.g. nitrogen
fixing plants such as clovers, tagastaste, acacias, lucerne, and casuarinas; and high humus producers such as
bananas). Foraging animals periodically allowed into the system also provide nutrients in the form of manure.
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2. Companion Planting and Composting, Hollard Gardens, 27 September 2009
• Facilitating root penetration:
Unlike grasses some plants offer an open root structure that does not interfere with the central plant’s ability to
feed at the soil surface (e.g. comfrey, winter and spring bulbs, comfrey, globe artichoke). Such plants should
be established in orchards in place of grass to boost productivity.
Grass is a poor companion to fruit trees as it interferes with surface root penetration
• Convenient harvesting:
It’s an interesting fact that plants that make good companions often taste great together too! So growing them
together not only improves their yield but also simplifies the job of harvesting. (e.g. marigolds grown with
tomatoes, parsley, basil deter nematodes and contribute petals to eat in salads; dill grown under apple trees
host predatory wasps and tastes great with apples raw or cooked).
How do we know what will benefit what?
Companion planting guides and other references offer a great starting point to beneficial guild assemblies for
Permaculture landscape design.
Observation is a good way to build upon this knowledge. You might even conduct a survey of plant and animal
associations in your local area to this end. Keep a look out for “accidental” guilds that you can emulate by
design:
You may notice, for example, that a neglected but flourishing apple tree is growing alongside acacia and
mulberry, with comfrey, nasturtium, iris and clover beneath it.
As you gather observations, you might also come to notice that healthy apple trees are never found near
walnut trees (walnut roots secrete growth inhibitors that apple trees are sensitive to).
Interactions - both positive and negative - may or may not be sensitive to the distance between elements.
Again, observation will provide the answer of how critical spacing is in your Permaculture landscape design.
Intervention strategy:
In the case of conflict between elements, such as between walnut and apple, neutral elements (e.g. mulberry
and acacia) that are not affected by walnut can be planted as a buffer separating them as an intervention
strategy in your design.
Taken from: www.small-farm-permaculture-and-sustainable-living.com
Composting
The how’s and whys
Making and using compost is the cornerstone of organic gardening - if you want to 'Grow Your Own', there's
no better place to start. The finished product is rich, dark, crumbly and sweet-smelling. It is made of recycled
garden and kitchen waste, and can also include paper products. It is used to feed and condition the soil and in
making potting mixes. Around 40 per cent of the average dustbin contents are suitable for home-composting
so it helps cut down on landfill too. Making compost is often considered to be complex but all you need to do is
provide the right ingredients and let nature do the rest. However, a little know-how will help you make better
compost, more efficiently.
Where do I make my compost?
There are a variety of bins on the market but they are all just a container for the composting process. A bin is
not strictly necessary. You can just build a heap and cover it over with some polythene or cardboard or build
your own. The ideal compost bin is: easily accessible, has no gaps in the sides and may be insulated with
cardboard or straw, has a lid or cover. And is located in a sunny or semi-shaded position, directly on the soil or
turf away from water-courses.
What can I compost?
Anything that was once living will compost, but some items are best avoided. Meat, dairy and cooked food can
attract vermin and should not be home-composted. For best results, use a mixture of types of ingredient. The
right balance is something learnt by experience, but a rough guide is to use equal amounts by volume of
greens and browns (see below). Some things, like grass mowings and soft young weeds, rot quickly. They
work as 'activators', getting the composting started, but on their own will decay to a smelly mess. Older and
tougher plant material is slower to rot but gives body to the finished compost - and usually makes up the bulk
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of a compost heap. Woody items decay very slowly; they are best chopped or shredded first, where
appropriate.
Compost ingredients
i. 'Greens' or nitrogen rich ingredients
Urine (diluted with water 20:1)
Comfrey leaves
Nettles
Grass cuttings
Other green materials:
Raw vegetable peelings from your kitchen
Tea bags and leaves, coffee grounds
Young green weed growth (avoid weeds with seeds)
Soft green prunings
Animal manure from herbivores eg cows and horses
Poultry manure and bedding
ii. 'Browns' or carbon rich ingredients - slow to rot
Cardboard e.g. cereal packets and egg boxes
Cardboard tubes
Newspaper
Bedding from vegetarian pets eg rabbit - hay, straw, shredded paper, wood shavings
Tough hedge clippings
Woody prunings
Old bedding plants
Bracken
Sawdust
Wood shavings
Fallen leaves can be composted but the best use of them is to make leafmould
iii. Other compostable items
Wood ash, in moderation
Hair, nail clippings
Egg shells (crushed)
Natural fibres eg. 100% wool or cotton
iv. Do not compost
Meat
Fish
Cooked food
Coal & coke ash
Cat litter
Dog faeces
Disposable nappies
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How do I make my compost?
You can make compost simply by adding compostable items to a compost heap when you feel like it. It will all
compost eventually but may take a long time and, if the mix is unbalanced, may not produce a very pleasant
end product. With a little extra attention you could improve things dramatically. If you want to produce more
compost in a short time, and are able to put more effort into it, follow the 'HOT HEAP' route.
An ideal mix
To make good compost you need a more or less equal amount of 'greens' and 'browns' by volume. You can
also include small amounts of the 'other ingredients'.
The cool heap route
1. Try, if possible, to collect enough compost materials to make a layer of at least 30cm or more in the
compost bin. Weed the garden, mow the lawn, empty the kitchen bucket! Mix in some straw, woody
prunings, scrunched up cardboard packaging - this helps create air spaces within the heap. It will help
if you place a few woody plant stems or small twigs on the bottom first as this will improve the air
circulation and drainage.
2. Continue to fill the container as and when you have ingredients. If most of what you compost is kitchen
waste, mix it with egg boxes, toilet roll middles and similar household paper and cardboard products to
create a better balance.
3. When the container is full - which it may never be as the contents will sink as it composts - or when you
decide to, stop adding any more. Then either just leave it to finish composting (which could take up to a
year) or go to Step 4.
4. Remove the container from the material, or the material from the container - whichever you find
easiest. If the lower layers have composted, use this on the garden. Mix everything else together well.
Add water if it is dry, or add dry material if it is soggy. Replace in the bin and leave to mature.
The hot heap route
1. Gather enough material to fill your compost container at one go. Some of this may have been stored in
a cool heap and have started to rot slightly. Make sure you have a mixture of soft and tough materials.
2. Chop up tough items using shears, a sharp spade (lay items out on soil or grass to avoid jarring) or a
shredder.
3. Mix ingredients together as much as possible before adding to the container. In particular, mix items,
such as grass mowings and any shredded paper, which tend to settle and exclude air, with more open
items that tend to dry out. Fill the container as above, watering as you go.
4. Give the heap a good mix. Within a few days, the heap is likely to get hot to the touch. When it begins
to cool down, or a week or two later, turn the heap. Remove everything from the container or lift the
container off and mix it all up, trying to get the outside to the inside. Add water if it is dry, or dry material
if it is soggy. Replace in the bin.
5. The heap may well heat up again; the new supply of air you have mixed in allows the fast acting
aerobic microbes, ie those that need oxygen, to continue with their work. Step 4 can be repeated
several more times if you have the energy, but the heating will be less and less. When it no longer
heats up again, leave it undisturbed to finish composting.
A hybrid route
There’s nothing wrong with doing a bit of both. Fill your heap as you create waste (as for the cool method),
then turn it when you have time. This will help it heat up. You can turn it as much or as rarely as you please -
the more often you turn the heap, the quicker your compost will be ready.
When is it ready?
Compost can be made in as little as six to eight weeks, or, more usually, it can take a year or more. In general,
the more effort you put in, the quicker you will get compost. When the ingredients you have put in your
container have turned into a dark brown, earthy smelling material, the composting process is complete. It is
then best left for a month or two to 'mature' before it is used. Don't worry if your compost is not fine and
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crumbly. Even if it is lumpy, sticky or stringy, with bits of twig and eggshell still obvious, it is quite usable. It can
be sieved before using if you prefer. Any large bits can be added back into your new compost heap.
Compost hints & tips
Autumn leaves
These can be added to your compost heap but the best use of them is to make leafmould. Stuff wet leaves
into black plastic sacks (loosely tied), or an open wire mesh container. The resulting leafmould is ready to use
after a year or two.
Grass mowings
Mix well with browns to avoid a slimy mess. Alternatively, leave on the lawn - they will soon disappear and
feed the grass; this will not cause 'thatch'. Can also be mixed into a leafmould heap.
Diseased plants
Plant materials suffering from soil-borne diseases such as clubroot and white rot should not be added to a
compost heap. Anything else can be safely composted in a hot heap. Diseases that don’t need living matter to
survive, such as grey mould, mildews, and wilts, may survive in a cold heap. But heat is not the only factor that
will kill diseases: the intense microbial activity in a compost heap also helps to dispose of them. Some
diseases, such as tomato and potato blight need living plant tissue to survive and will not last long without it. It
is fine to add foliage suffering from these diseases to your hot or cold compost heap. If in doubt, leave it out.
Problem materials can be sent to your local council green waste recycling facility where the composting
methods are hot enough to kill any problem organisms.
Perennial weeds
Some perennial weeds will be killed in a hot heap; avoid really persistent bad weeds. Don't burn or dump
these weeds - they are rich in plant foods. Mix with grass mowings in a plastic sack. Tie it up and leave for a
few months until the weeds are no longer recognisable, then add to the compost heap. Or send them to your
local council green waste recycling facility where the composting methods are hot enough to kill them off.
Weed seeds
Weed seeds may survive a cool heap, but should be killed in a hot one. If your finished compost tends to grow
weeds, dig it in rather than spreading it on the soil surface.
Hedge clippings and prunings
Chop or shred tough prunings and clippings from evergreen hedges before adding to a mixed compost heap.
Compost large quantities separately; even unshredded they will compost eventually. Mix with grass or other
activating material; water well. Tread down the heap, then cover. In anything from a few months to a few years
you will have a coarse mulch which can be used on perennial beds.
Animal manures
Strawy horse and cattle manure composts well. Manure mixed with wood shavings should be left to rot until
the shavings have decomposed. If it is dry, water well and mix with grass mowings, poultry manure or other
activating (ie ‘greens’ that are nitrogen rich) material. When rotted use as a surface mulch. Small pets, like
hamsters, don't produce many droppings but you can still use their waste as a strawy addition to the compost
heap. Guinea pigs are marvellous - they love eating weeds and convert them quickly to prime compost
material!
Paper products
Newspaper can be added to a compost heap, but in any quantity it should go for recycling into more paper.
Cardboard, paper towels and other paper items can be scrunched up and composted. They are particularly
useful where kitchen scraps make up a high proportion of the compost ingredients. Glossy paper takes a long
time to rot down. Coloured inks are quite safe to compost.
Sawdust and wood shavings
Very slow to decay. Raw or uncomposted wood shavings incorporated into the soil can lock up soil nitrogen,
making it unavailable for plants for a year or more. Add in small quantities; balance with quick-to-rot activating
materials. See also 'Animal manures' above. Do not use if treated with wood preservatives.
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Composting questions answered
Is garden compost the same as bagged 'multipurpose' compost?
No. Sowing, potting and multipurpose composts that you buy in garden centres are mixtures of various
materials such as shredded bark, sand, coir and fertilisers. These are used for raising seedlings and growing
plants in pots.
Will a compost heap breed pests?
Compost is made by a host of small and microscopic creatures. These are not pests and will not overrun your
garden. Slugs are often found in compost heaps - some species feed on decaying organic matter and are a
valuable part of the composting process.
Do I need any special equipment?
A garden fork is the only essential item for turning and spreading compost. A compost bin keeps everything
neater but it is not essential.
Will a compost heap attract rats?
Rats may visit a compost heap if they are already present in the area but composting does not generally
attract the rats in the first place. If rats or mice are nesting in your compost heap, this is a sign that the heap is
too dry. Add water until it has the consistency of a wrung-out sponge.
Is compost safe to handle?
Yes, if the usual garden hygiene rules are followed. Keep cuts covered, wash hands before eating and keep
your anti-tetanus protection up to date.
Does a compost heap have to get hot?
No. A medium-sized compost heap can heat up to 60oC in a few days. The heat helps to make quicker
compost, and to kill weeds and diseases. But your compost may never heat up, especially if it is made over a
long period. The compost can be just as good, but it will take longer to be ready for use.
Does compost spread weeds and diseases?
Some weed seeds and plant diseases will survive in a slow, cool compost heap - if you add them in the first
place.
Do I need a shredder to make compost?
No. A shredder can be very useful where there is a lot of woody material to be composted, but it is not
essential.
Can I compost poisonous plants?
Yes. The toxins from rhubarb, yew, laurel and other poisonous plants are all broken down during the
composting process and will not cause any damage to you or your garden.
Ants are nesting in my compost heap. Help!
Ants do have some small part to play in the composting process but the presence of nests in the heap is a
sign that it is too dry. Water it thoroughly, or, if some parts are wetter than others, give it a good mix or turn.
Every time I open my bin I am assailed by masses of tiny 'fruit flies'? Why is this?
These are part of the decomposition process but their numbers can be reduced by burying any fruit waste
among other ingredients. Flies are also a sign that the compost is a little too wet or has too many 'green'
ingredients. Make sure that the bin has a lid and add 'brown' ingredients such as straw, cardboard or paper to
re-balance the heap. Mix it in well.
There's a wasps nest in my bin? What shall I do?
There is no 'organic' way to get rid of wasps. However, they do not return to the same nest every year so the
problem will be over when autumn comes. If you can, leave the wasps alone as they are useful predators for
garden pests. If they cannot be left (in a school garden, for example) then call your local council's
Environmental Health Department for advice. To avoid the problem in future, make sure that your heap does
not get too dry, make sure it has a lid and that the sides are solid, with no air gaps.
Taken from: http://www.gardenorganic.org.uk/organicgardening/compost_pf.php
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Some of the many other composting methods
I. Sheet Mulching
A gardening and landscaping method that allows planting into or on top of the ground and is a form of
no-dig gardening: the process of covering any base or unwanted plant material including weeds, old
lawn or open ground with layers of material known as the "barrier", "compost" and "mulch" layers
II. Trenching
A method where a trench is dug and filled with kitchen scraps, leaves, twigs, lawn clippings, and the
original topsoil. The area can be used for planting after between a month and a year.
III. Compost Tea
Compost tea is a liquid solution or suspension made by steeping compost in water. It is used as both a
fertilizer, a compost starter and in attempts to prevent plant diseases (it has a high concentration of
microbes).
IV. Green Manure
In agriculture, a green manure is a type of cover crop grown primarily to add nutrients and organic matter to
the soil. Typically, a green manure crop is grown for a specific period, and then plowed under and incorporated
into the soil. Green manures usually perform multiple functions, that include soil improvement and soil
protection:
Leguminous green manures such as clover and vetch contain nitrogen-fixing symbiotic bacteria in root nodules
that fix atmospheric nitrogen in a form that plants can use.
Green manures increase the percentage of organic matter (biomass) in the soil, thereby improving water
retention, aeration, and other soil characteristics.
The root systems of some varieties of green manure grow deep in the soil and bring up nutrient resources
unavailable to shallower-rooted crops.
Common cover crop functions of weed suppression and prevention of soil erosion and compaction are often
also taken into account when selecting and using green manures.
Some green manure crops, when allowed to flower, provide forage for pollinating insects
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