Companion Planting Fact Sheet and Community Gardening Basics - Australia

1. Companion Planting
Co mmu nit y
Gardenin g
Ba si cs
In fo sh ee t # 5
It i s n ot n o r mal f o r a n y liv i ng t h i n g to Nitrogen fixing
gr ow i n i s ola t i o n , o r i n c o n t a c t w i t h o nl y Leguminous plants host bacteria in their roots. These
ot h e r s o f t h e sa me k in d . D iv e rs i t y an d bacteria fix nitrogen, supplying this nutrient to their
hosts and indirectly, to neighbouring plants. Example:
in te r c on ne c t i o n are b a si c e c ol ogi cal
clover grown around cauliflower.
pri n c i ple s. C o m pa ni o n p la n t ing c re a te s a
di v er si t y of s p e c ies w i th i n t he g a r de n . Allelopathy
Care f ul ly a rra nge d p l an ts as sis t e a c h Substances released from plants into the soil can
ot h e r ’s g r ow th by r e d u c ing p e s t n u mbe rs affect the growth of neighbouring plants. Many plants
an d c re a t in g f a v ora ble g r o wi ng inhibit the growth of others, but a few enhance it.
c on di ti on s . . Example: plants promoting the growth of others
nearby include nettle, calendula, yarrow and (planted
sparingly) chamomile.
Scent
Strongly scented herbs mask the scent of other plants,
Minerals
confusing pests, which identify their targets by smell.
Deep-rooted plants draw up minerals from the
Example: broccoli and cabbage will suffer less damage
subsoil, returning them to the topsoil. Example:
from the caterpillars of the cabbage white butterfly when
comfrey draws up potassium, which is released into
planted among sage, rosemary or dill.
the soil as the leaves die off in late autumn.
Attracting Predators
Bad Companions
Providing food and habitat for insects that are predators
Plants to avoid planting near others include large
or parasites of insects that damage plants can reduce pest
trees, (particularly conifers, eucalypts and walnuts),
numbers. Example: parsnip flowers are a food for
strongly bitter herbs (wormwood, southernwood,
parasitic wasps.
tansy, rue) and heavy feeders which may also release
growth inhibitors (brassicas, sweet corn, sunflowers).
Repelling or killing pests
Some plants are toxic to pests. Example: French
Intercropping
marigolds will kill off some harmful nematode species.
Save space by growing small, quick growing
vegetables between larger slower growing ones.The
Altering appearance
small vegetables can be harvested before the larger
Flying pests often identify their food supply by its shape.
From Growing Community: Starting ones claim their growing space.
Growing different plants closely together means that there
and Nurturing Community Gardens.
are no distinctive outlines for pests to identify. Example:
Originally written by David Guilds
Corkill for organic gardening weeds grown amongst mung beans keep down beanfly
A small number of plants which all grow well
courses at Fern Ave Community numbers.
Garden. May be reproduced together is called a guild. A common three-plant
freely for use in community combination is sweet corn, pumpkin and climbing
gardens. Additional copies Shelter
bean. A common four-plant combination is tomato,
available from A carefully placed stand of taller plants creates a
basil, marigold, and lettuce.
http://www.canh.asn.au/projects/ sheltered spot by providing shade and alleviating wind.
community-gardens.aspx Other factors to consider when deciding what to
Example: plant corn near pumpkins.
plant with what include: size, growth rate, root depth
and type, nutritional needs, soil conditions, soil type
Support
and watering needs.
The stalks and branches of a large sturdy plant can
support a climber. Example: sweet peas climbing through
the low-lying branches of an orange tree.