PlotPlan

Companion planting chart

Which vegetables and herbs make good neighbours, which are traditionally kept apart, and why. Pick a crop to see its friends and foes.

Tomato

Nightshades · Heavy feeders that share early blight, late blight and soil-borne wilts.

Good companions

AsparagusBasilCarrotChivesCilantroGarlicLettuceMarigoldOnionParsleyPepper

Keep apart

BroccoliCabbageCauliflowerDillFennelKaleKohlrabiPotatoSweet corn

Plant deep: stems buried in soil grow roots. Stake or cage at planting, not after. Full tomato guide

Companion planting matrix

Eighteen of the most-planted crops against each other. ✓ good companions, ✗ keep apart, blank = no strong effect either way.

CropTomatoPepperPotatoBush beanPeaCabbageBroccoliCarrotOnionGarlicLettuceCucumberZucchiniSweet cornBasilDillMarigoldStrawberry
Tomato✓✗✗✗✓✓✓✓✗✓✗✓
Pepper✓✗✓✓✓✓
Potato✗✓✓✗✗✓✓
Bush bean✗✓✓✗✗✓✓✓✓
Pea✓✗✗✓✓
Cabbage✗✓✓✓✓✓✗
Broccoli✗✓✓✓✗
Carrot✓✓✓✓✓✓✓✗
Onion✓✓✗✗✓✓✓✓✓✓
Garlic✓✗✗✓✓✓
Lettuce✓✓✓✓✓✓✓✓✓
Cucumber✗✓✓✓✓✓✓
Zucchini✗✓✓✓
Sweet corn✗✓✓✓✓
Basil✓✓
Dill✗✓✓✗✓✓✓
Marigold✓✓✓✓✓✓
Strawberry✗✗✓✓✓

Why some pairings work

  • Trap crops. Nasturtiums draw aphids and flea beetles away from brassicas; you sacrifice a few plants to protect the rest.
  • Feeding the good bugs. Dill, cilantro and marigolds flower readily and feed hoverflies and parasitic wasps, whose larvae eat aphids and caterpillars.
  • Sharing space. Fast radishes between slow carrots, or lettuce in the shade of tomatoes, use ground that would otherwise sit empty.
  • Physical support. Corn stalks carry pole beans; squash leaves shade the soil.

Why some pairings don't

  • Shared diseases. Tomatoes and potatoes both get late blight, the disease behind the Irish potato famine. Keep them apart in space and in your rotation.
  • Shared pests. The corn earworm is the same insect as the tomato fruitworm.
  • Competition. Sprawling squash smothers anything short; sunflowers shade their neighbours.
  • Folklore. Beans vs onions and fennel vs nearly everything are old warnings with thin evidence. Keeping them apart costs nothing.

The garden planner flags these pairs automatically when you put them in neighbouring squares.

Questions gardeners ask

What is companion planting?

Growing plants next to each other because they help, or at least don't hinder, one another: by attracting beneficial insects, confusing pests, sharing space efficiently or providing support, as corn does for climbing beans.

Is companion planting backed by science?

Partly. Trap crops, flowering plants that feed predatory insects, intercropping and marigolds grown as a nematode-suppressing cover crop have research behind them. Many popular pairings, like tomatoes and basil for flavour, are tradition with little evidence. The chart marks traditional pairings; use them as a guide, not a law.

What should not be planted next to tomatoes?

Traditionally potatoes (they share early and late blight), fennel, corn (corn earworm and tomato fruitworm are the same insect) and cabbage-family crops. Good tomato neighbours include basil, marigolds, carrots, parsley, onions and lettuce.

Why do beans and onions not go together?

Gardeners have long reported that onions, garlic, leeks and chives stunt beans and peas. The evidence is anecdotal, but since both are easy to place apart, most planners simply keep them in separate squares.

What is the three sisters method?

A polyculture developed by Indigenous peoples of North America: corn provides a pole, beans climb it, and squash covers the ground to shade out weeds and hold moisture.