Companion planting

Friendly neighbors and a few combinations to give extra space. Pairs with What can I grow? when you are sketching beds. For fallow gaps and soil recovery, see cover crops.

Type

All Good neighbors Give space

Crop focus

Any Tomato Pepper / eggplant Brassicas Squash / cucumber Beans / peas Carrot / root crops Corn Lettuce / greens Radish Onion / garlic Herbs

Benefit

Any Pest confusion / trap Pollinators Shade or shelter Soil / roots Kitchen / flavor

Cucumber & radishPair
Cucumbers · Radishes
Radishes mark rows and mature fast while cucumbers warm up; radishes can flag soil crusting issues early.
Nasturtium & cucurbits (trap crop idea)Pair
Nasturtium · Cucumber / squash
Aphids often prefer nasturtium; some growers sacrificially host aphids there. You must still scout—this is not automatic control.
Calendula near vegetablesPair
Calendula · Mixed veg bed
Long-blooming calendula supports generalist pollinators; some predatory insects visit composite flowers—pair with good habitat, not sprays.
Avoid: vegetables under black walnutAvoid
Nightshades / cucurbits (many) · Black walnut canopy / roots
Juglone from walnut roots and litter harms many vegetables. Map walnut driplines and keep food beds outside that zone or use raised beds with barriers—research your species.