The Greenhouse Companions I Would Never Grow Tomatoes Without

Tomato and Basil Grown together smells devine!

Every gardener has their little rituals. The old habits that return each spring almost without thinking. Seed trays appear on windowsills, muddy boots gather by the back door, and suddenly every available surface seems to hold a pot labelled in slightly smudged handwriting.

For me, one of those rituals is planting basil and French marigolds alongside my tomatoes in the greenhouse.

Some people may think it looks a little chaotic compared to neat rows of tomato plants standing proudly on their own, but I have always loved a greenhouse that feels alive and abundant. And over the years, I have found these companion plants earn their place time and time again.

The basil always comes first.

Even brushing past it on a warm afternoon releases that unmistakable sweet peppery scent that instantly makes me think of summer lunches, garden gatherings and simple meals eaten outdoors.

There is something wonderfully Mediterranean about tomatoes and basil growing together, even if outside the Dorset weather is doing its usual best to convince us otherwise.

Of course, gardeners will tell you basil is believed to help improve the flavour of tomatoes, though whether that is science or simply wishful thinking, I couldn’t honestly say. But somehow it feels right growing them side by side when they end up together on the plate anyway.

And practically speaking, the basil enjoys the same warm greenhouse conditions as the tomatoes, thriving happily beneath their leafy canopy. By midsummer I can usually pick handfuls at a time for salads, homemade pesto or torn generously over roasted tomatoes with olive oil and sea salt.

Then there are the French marigolds — bright little bursts of sunshine tucked between the pots.

I plant them partly because they are cheerful and make the greenhouse feel less functional and more like a proper little garden retreat. Their fiery oranges and golden yellows glow beautifully amongst all the green foliage, especially on dull rainy days when summer still feels frustratingly far away.

French Marigolds

But they also have a purpose.

French marigolds are famously used as companion plants because their strong scent is thought to help deter whitefly and other troublesome greenhouse pests. Whether they perform miracles or not, I do notice fewer problems when they are there, and at the very least they seem to distract the insects long enough for the tomatoes to get on with growing.

There is also something rather comforting about mixing flowers amongst vegetables. It softens the greenhouse somehow. Makes it feel less about production and more about pleasure.

By high summer, when the tomato vines are heavy with fruit, the basil is thriving and the marigolds are glowing in every corner, the greenhouse becomes one of my favourite places to be. Hot, fragrant and buzzing quietly with life.

And perhaps that is the real beauty of companion planting. Not simply what it may do for the tomatoes, but the atmosphere it creates. A little Dorset greenhouse full of colour, scent and the hopeful promise of summer meals still to come.