Good friends describe me as “herbal”. I’ve been a lentil eater for 27 years and my shelves groan with organic gardening and vegetarian recipe books. And I’m not averse to dabbling in a spot of ancient-learned-women’s-plant-knowedge-as-yet-unverified-by-modern-experimental-science. But I have to say that companion planting has taken a body blow in our household in recent weeks. Here’s why:
 Two kale plants, from the same punnet, planted less than a metre apart. On your left, the kale that enjoyed the companionship of a cheerful red and orange flowered marigold, “Naughty Marietta”. On your right, the kale out in the cold with no date (though giant mustard, baby leeks and daikon radish are hanging around in a kind of unstructured way).
It turns out that the vague story I heard about marigolds, with their pungent foliage, as a nifty companion plant is true enough if you have a problem with nematodes, but dead wrong on the aphid front. It seems that all-female parthenogenic parasites love the cheery flowers of marigolds even more than I do. But not enough to turn down the opportunity for a feast on a superfood.
In fact, I read recently that if you rub some vaseline on a yellow sticky label and stick it in amongst your veggies, the aphids will be lured in and get stuck on the lube so you can dispose of them thoughtfully. But I’d advise you not to get too carried away with this approach, for a number of reasons: (a) if left long enough your post-it might attract aphids from further afield (b) striding out back with a bundle of stationery in one hand and a tube of vaseline in the other will raise eyebrows amongst your neighbours and (c) the veracity of this story is no more guaranteed than the one about the marigolds and the aphids.
I’m not dissing the power of the herb entirely though. It seems the smell of granny’s hanky does distract possums and bandicoots (and perhaps singing mice and super rats) from sniffing out newly sprouted peas and beans. My broadies and sugar snaps are looking good under a vegenet liberally sprinkled with lavender flowers and leaves. I hold out hopes that this continue to work, significantly reassured by the fact that absolutely no one, as far as I know, recommends these as companion plants.