Understanding Companion Planting

Companion Planting - a gardening fact sheet by the Green Life Soil Co.

Companion planting involves the strategic placement of plants, especially vegetables and herbs, to leverage their beneficial effects on one another. This method can significantly enhance garden productivity and health.

Here's a breakdown of how companion planting works and why it's beneficial:

Physical Benefits

Shelter and Protection: Taller plants can provide shade and wind protection for more delicate plants.
Maximizing Space: Climbing plants can be trained to grow over taller plants, increasing production in limited spaces.
Root Depth: Plants with different root depths don't compete for water and nutrients.

Nutritional Benefits

Nitrogen Fixing: Legumes (e.g., peas and beans) have root nodules that convert atmospheric nitrogen into a form usable by plants, promoting the growth of nearby plants.
Soil Aeration: Deep-rooted legumes help aerate the soil, benefiting neighboring plants and loosening compacted soils, increasing drainage and improving airflow to root systems.

Pest Control

Visual Confusion: Some plant shapes and flower configurations can confuse insect pests.
Scent Masking: Strong-smelling herbs can mask the odors of other plants, confusing pests seeking their target.
Sacrificial Plants: Sometimes you'll find insect pests will prefer a species over another - make a note; and include sacrificial plants each season.

Chemical Interactions

Growth Stimulants: Some plants release chemicals from their roots that can stimulate the growth of neighboring plants.
Germination Inhibitors: Certain plants emit chemicals that can inhibit the germination of other seeds, which can be strategically used to manage plant growth.

Practical Tips

Scattered Groupings: Planting in scattered groupings rather than neat rows helps confuse pests and isolate infestations, reducing widespread damage.
Aim for biodiversity: Add flowering plants in and around your vegetable garden to attract beneficial insects and aid pollinators.

Effective Plant Pairings

While opinions on plant pairings can vary, some general consensus exists on good and bad companions. For instance:

Good Companions: Tomatoes and basil, beans and corn, carrots and onions.
Bad Companions: Beans and onions, tomatoes and potatoes, cucumbers and aromatic herbs.

Get Personalised Help

Companion planting can get rather complicated! However, studies have shown that it works well in promoting plant health and deterring pests, even if it's not 100% foolproof.

If you're having any issues with companion planting or need more personalised advice, stop by our store. Our experts are here to help you create a thriving vegetable garden. Come in and ask for help today!

Guide Chart of Companion Planting in Perth

*Plant*	*Good Companion*	*Bad Companion*
Artichoke	Cucumber	Potatoes
Asparagus	Basil, parsley, tomatoes, marjoram	-
Beans	Carrot, celery, cabbage family, peas, cucumber, potatoes, parsnip, lettuce, parsley, eggplant, marigolds	Beetroot, fennel, onion, garlic, kohl rabi, sunflowers
Beetroot	Kohl rabi, onion, silverbeet, lettuce, cabbage family, dill, lovage, marjoram	Beans, tomatoes
Cabbage family (broccoli, cabbage, cauliflower, Brussels sprouts)	Beetroot, celery, dill, chamomile, onion, mint, potatoes, rosemary, sage, thyme, lavender, hyssop, nasturtium, tansy, beans, peas, coriander, marigolds, lettuce	Rue, strawberries, tomatoes, garlic
Carrots	Chives, lettuce, onion, leek, peas, rosemary, sage, tomatoes, radish	dill
Celery	Beans, cauliflower, cabbage, leek, tomatoes, dill	-
Corn	Beans, cucumber, peas, potatoes, pumpkin, squash, melons, parsnip, zucchini	-
Cucumber	Beans, chives, corn, Jerusalem artichoke, peas, sunflower, tomatoes, celery, lettuce, nasturtium	-
Eggplant	Beans, marjoram, potatoes	-
Leek	Carrot, celery, onion	Beans, peas
Lettuce	Carrot, cucumber, onion, radish, strawberries, beetroot, marigolds	-
Onions, Garlic	Beetroot, chamomile, carrot, lettuce, radish, cabbage family, tomatoes, silverbeet, strawberries (onions but not garlic),	Peas, beans, potatoes
Parsnip	Peas, potatoes, beans, radish, garlic	Carrot, celery, caraway
Peas	Beans, carrot, cucumber, corn, radish, swede, turnip, squash	Onion, garlic, potatoes, shallots
Potatoes	Beans, cabbage family, corn, eggplant, horseradish, marigolds, peas, nasturtium, parsnip	Cucumber, pumpkin, sunflower, onions, tomatoes, rosemary
Pumpkin/squash, zucchini	Corn, nasturtium, marjoram	Jerusalem artichoke, potatoes
Radish	Carrot, chervil, lettuce, peas, onions, nasturtium, parsnip	Hyssop
Spinach	Strawberries, beetroot, onion	-
Silverbeet	Lavender, marigolds	-
Strawberries	Bush beans, borage, lettuce, spinach, silverbeet, onion (not garlic)	Cabbage family, tomatoes, garlic
Swede	Onions, peas	-
Tomatoes	Asparagus, basil, carrot, chives, mint, nasturtium, parsnip, onion, corn, borage, parsley, marigold, celery	Rosemary, potatoes, dill, kohl rabi, fennel, strawberries
Turnip	Peas, nasturtium	-

(References: ‘Companion Planting in Australia' by Brenda Little, Reed Books & ‘The Backyard Organic Garden’ by Keith Smith, Lothian Press)

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Products for Companion Planting

There are several products that are perfect for companion planting from our range. If you need help or advice to choose what’s best for you – please contact us today!