Hokianga Heirloom Tomatoes
What Is Companion Planting?
Companion planting is really about understanding how plants relate to each other. Some plants release chemicals that can inhibit the growth of others. Some can support their neighbours by attracting beneficial insects. And even after plants die, their roots and residues can continue influencing the bacteria, fungi and other organisms living beneath the soil.
To keep it simple, good companions make good gardens.
With a little knowledge and careful observation, you will not only prolong your harvest, but you can create a feast for the eyes.
But I think there is more to it than that.
“…the whole is something beside the parts…”
— Aristotle, Metaphysics, Book VIII
Beyond Companion Gardening
Did you know zebras are black and white, making them stand out on the horizon, but those same stripes can help them vanish under moonlight? I was surprised too.
What seems like an obvious visual mismatch makes perfect sense once you understand the context. At night, when lions hunt, a zebra's stripes can make it incredibly difficult to see in the low light. It's a reminder that nature's wisdom can hide in plain sight if we look closely.
The ability to look at things through different lenses can lead to deeper understanding — and perhaps better decisions in the wider context.
Want to see this thinking in action?
Take a look at Marigolds Everywhere and discover why there may be much more to this familiar garden flower than meets the eye.Secrets Hidden In The Soil
Companion planting isn't new. Long before chemicals like Roundup existed, people were growing food by observing seasons, soils, insects and the relationships between plants.
But somewhere along the way, the scale changed.
We developed systems where one person and increasingly powerful machinery could manage enormous areas of land. Food could be grown far from the people who would eventually eat it, moved through supply chains and sold through businesses that also needed to make a profit.
That scale brought efficiencies, but it also changed the way we solved problems.
A weed growing amongst a few rows of vegetables can be pulled, mulched, shaded out or simply tolerated. Scale that weed across hundreds of hectares and suddenly the problem — and the solution we reach for — looks very different.
Roundup didn't create industrial agriculture. But products like it became extraordinarily useful to the agricultural system we created.
And that leaves me wondering about something much smaller.
What happens to the relationships beneath our feet when we simplify what is growing above them?
What happened to the garden beneath the garden?
"Ko te rongoā kei te piringa." - The remedy is in the relationship.
Companion Planting History
And now we have the technology to investigate whey some of it works
Plants don’t just grow, they strategise. Alongside the essential compounds they need to survive (called primary metabolites), plants also produce secondary metabolites, powerful substances designed to serve specific purposes. These might make a leaf taste bitter to stop a hungry grazer, or help a flower attract the exact insect it needs for pollination.
What’s remarkable is how many of these natural compounds have been harnessed for medicines, flavourings, fragrances, and even pesticides. So before reaching for a chemical spray, ask yourself:
Have I understtod what the plant is already doing for itself?
Companion Gardening
A cottage garden tradition
We have been miseducated about gardening. Weeding and leaving the soil bare weaken our gardens. We were told that weeds compete for nutrients and light, but it's important to remember the context for a deeper understanding, like in my zebra story.
Keeping the soil covered with living plants helps suppress unwanted growth, protects the earth from harsh rain and drought, and strengthens the overall ecosystem.
Personally, I avoid the word weed. It carries a heavy implication, not just for the plant, but for how we relate to nature itself.
One person's weed is another man's wild flower - Dave Goulson.
Dave Goulson is the author of "Silent Earth: Averting the Insect Apocalypse."
A Living Tradition from the Cottage Garden
Let your plants not pesticides do the heavy lifting
The roots of companion planting can be found in the traditional cottage gardens of Europe, where vegetables, herbs and flowers grew together in small spaces around the home.
These gardens weren't designed from theory. Knowledge grew through generations of observation — which plants worked together, what attracted insects, what struggled, and what helped keep the garden productive.
As access to land changed, many of these ideas continued in allotment and community gardens.
It wasn't just beautiful. It was practical.
Traditional Companions for Tomato Plants
Companion planting guides often divide plants into “good” and “bad” neighbours for tomatoes. I think that's a useful starting point — but not a rulebook.
Your soil, climate, spacing, water and the job you want a plant to perform all matter.
Ask why the relationship might work before deciding whether it belongs in your garden.
Good Vegetable Companions
asparagus, basil, cabbage, carrot, celery, chives (to the front of the border), onion, parsley, pea
Bad Vegetable Companions
red cabbage, potato, beetroot and kohlrabi
Good Herb Companions
borage, lemon balm, and sage
Poor Herb Companions
dill, rosemary, fennel
Last but not least, and the most important
MARIGOLDS WITH EVERYTHING!
