Free tool
Companion planting checker
See which crops grow well next to each other and which to keep apart — or pick two crops to check whether they get along.
See what grows well alongside it and what to keep apart.
Plant near
Keep apart
Why keep these apart
Tomatoes and potatoes are both in the nightshade family and share the same late blight (Phytophthora infestans), which spreads fast in a warm, wet British summer — growing them side by side lets the disease jump straight from one to the other. Brassicas like kale and broccoli are greedy feeders that compete for nitrogen and prefer firmer, limed soil than tomatoes want.
Keep away from potatoes — both can carry blight. This is traditional guidance — the evidence for much of companion planting is thin, so treat it as a gentle nudge rather than a rule.
How to use it
Stay in One crop mode to plan around a single vegetable: choose a crop and you'll see a green Plant near list of good neighbours and an amber Keep apart list of ones to separate, each linking to our growing guide for that crop. Switch to Two crops mode when you just want to settle a single question — pick any two crops and the tool tells you whether they're best together, best apart, or have no strong preference. Everything updates as you choose, with nothing to submit, and your last selection is remembered on this device.
How the guidance works
The pairings come from long-standing British allotment and kitchen-garden tradition. A few rest on real mechanisms — legumes such as peas and beans fix nitrogen that hungry brassicas can use the following season, and pungent onions, garlic and leeks are often planted beside carrots to confuse carrot root fly. Others, like keeping tomatoes away from potatoes, are sensible disease hygiene: both carry blight, which thrives in our damp summers. Plenty of the rest is folklore with thin or mixed evidence, so we've kept the lists short and honest. Use them to nudge your bed layout and crop rotation, then trust your own observations from year to year — your soil, site and weather matter far more than any single pairing.
Frequently asked questions
- Does companion planting actually work?
- Some pairings have real, tested benefits — beans and peas fix nitrogen for the crop that follows, and strong-scented alliums next to carrots can help mask the scent that draws carrot root fly. But much of the traditional folklore is anecdotal and poorly evidenced. Treat this tool as a gentle nudge for your bed layout, not a guarantee.
- Why keep tomatoes and potatoes apart?
- Both are in the same family and share the same diseases — most importantly potato and tomato blight, which spreads quickly in the warm, wet UK summers. Growing them apart (and rotating where each goes year to year) reduces the chance of one passing problems to the other.
- What are the 'Three Sisters'?
- It's a classic trio of squash, climbing beans and sweetcorn grown together: the corn gives the beans something to climb, the beans feed the soil with nitrogen, and the sprawling squash leaves shade the ground and smother weeds. In a cooler UK garden it works best in a warm, sheltered, sunny spot.