The Best Plant Companions

Anyone who observes their garden closely over several years will notice that some plant pairings thrive side by side, growing together in perfect harmony all summer long – while others seem to repel one another, slowly retreating until one eventually disappears.

Plants that love each other - and those that don’t

Take marigolds and thyme, for example: they simply don’t get along. Usually, the marigold loses out, though sometimes both plants fail to thrive. It’s a little-known but easily verifiable fact. However, it’s worth remembering that thyme loves the sun - in shady spots, it will struggle even without marigolds nearby. Wild strawberries, on the other hand, make excellent companions for thyme.

Roses and lavender, by contrast, are often considered the perfect match - although it’s rarely true that lavender alone keeps aphids at bay. What many gardeners don’t realise is that roses and lavender actually prefer very different soil conditions, which makes this partnership more complicated than it seems. Roses are extremely fussy about their “luxury” soil - not too wet, not too dry, not too rich, not too poor, not too warm, not too cold. Whereas lavender thrives best on stony ground that stays warm. Interestingly, lavender also pairs beautifully with tomatoes, which, however, dislike being planted close to other members of the nightshade family.

Aubergines, peppers, chillies, and potatoes have similar growing requirements to tomatoes and therefore don’t complement them well, neither in terms of soil conditions nor potential pests. The Colorado potato beetle, for instance, doesn’t usually go for tomatoes, yet it’s been observed to infest tomato plants growing right next to potatoes.

This means that some plants simply don’t “get along” and avoid each other, while others with similar needs also make poor companions because they can’t support each other, above or below ground. Potatoes, for example, don’t get on with pumpkins or sunflowers. Kohlrabi and spinach, however, make good neighbours for potatoes. Why? They release different substances into the soil through their metabolism, creating a beneficial exchange that promotes growth. Plus, they also mature at different times.

There’s another reason to plan your plant companions carefully: the time-tested friendship of sage, thyme, and peppermint with cabbage plants. These aromatic herbs help keep the cabbage white butterfly, the small white culprit whose larvae can devastate cabbages, at bay. Adding celeriac to your cabbage patch also helps deter pesky flea beetles.

Good and bad neighbours:

Plant	Good neighbours	Bad neighbours
Potatoes	Caraway, coriander, spinach, kohlrabi, corn, nasturtium	Pumpkin, tomato, sunflowers, celery
Strawberries	Garlic, cabbage, leeks, radish, onions, lettuce, beans, chives, spinach	Potatoes, cabbage
Cabbage heads	Celery, sage, thyme and peppermint, celery, basil	Strawberries, garlic, onion
Kohlrabi	Potatoes, pumpkin, beans, peas, lettuce, tomatoes, radishes, beets, celery, spinach, leeks	Kohlrabi, in turn, goes well with almost everything.
Pumpkin	Kohlrabi, corn, peas, beans, radish, daikon radish	Potatoes, tomatoes, peppers, onions
Tomatoes	Parsley, lavender, garlic, cabbage, kohlrabi, nasturtium, onion, spinach, basil, beans, carrots, leeks	Eggplant, bell peppers, chilli peppers, potatoes, peas, fennel, beets, cucumbers
Peppermint	Grape vine (helps against powdery mildew)
Marigolds	Potatoes, cabbage (increases crop yield, promotes soil health)	thyme
Roses	Lavender and many other flowering plants
Sage	Thyme, rosemary
Celery	Cabbage heads	Potato, corn
Spinach	Tomatoes, potatoes, cabbage, kohlrabi, radishes, daikon radish, Chinese cabbage, strawberries	Beetroot, onion
Thyme	Wild strawberries, rosemary, sage	Basil (stunted)

Find high-quality seeds for your garden here:

• Vegetable seeds
• Herb seeds