Companion Planting Guide

Pick a plant to see what it grows well beside and what to keep it away from. Pairings are the classic, widely-published ones, a mix of tradition and trial, so treat them as guidance for arranging your beds.

About this tool: does companion planting actually work?

Pick a plant

Intercrop planner

Search for two or more plants to see whether they actually want the same space at the same time. The cross-section shows what each one occupies above and below ground.

Add a plant

Compress the scale for large plants

Companion planting mixes solid science (trap crops, scent masking, pollinator draws, nitrogen fixing) with garden lore. Use it to arrange beds and rotate families, but your own results and local pests are the final word.

Your plants

Add your own plant

Define a plant that isn't in the list. It shows up here and in the Garden/Plot/Bench Planner & Scheduler with your spacing, color, and companions.

Name

Type

Spacing (in)

Color

Root depth

Mature height (in)

Mature spread (in)

All three are needed for the intercrop planner above, which compares what plants occupy above and below ground. Leave them blank and the plant still works everywhere else.

Companions

Mark which plants it grows well with or should be kept apart from.

About this tool: does companion planting actually work?

What the evidence supports

Companion planting mixes evidenced ecology with folklore on the same chart, and published charts contradict each other. Pairings with a stated mechanism are the ones with support behind them.

What has real evidence

Dilution. Pests find a solid block easily and a scattered crop much less so.
Insectary planting. Dill, yarrow and alyssum feed hoverflies and parasitoid wasps, whose larvae eat your aphids.
Trap cropping, if you then deal with the trap crop.
Structure and shade. Three sisters is real engineering, and shade delays bolting.

What to do with all this

The reliable version is diversity plus rotation: mix families within a bed, keep something in flower, and move each family on a three or four year cycle. Bad neighbours are usually just competition or a shared pest. Marigolds and legume nitrogen are both weaker than their reputation.