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
Crop focus
Benefit
- Tomato & basilPair
Tomatoes · Basil
Classic neighbors: basil likes similar warm soil and steady water; flowers draw small beneficials when you let a few bolt late.
- Tomato & marigoldPair
Tomatoes · French marigold (Tagetes patula)
Traditional companion: strong scent may mask tomato host cues for some pests; root exudates are debated—treat as a helpful row edge, not a pesticide.
- Lettuce under tomatoes (spring)Pair
Lettuce / arugula · Tomatoes (young)
Early lettuce enjoys light shade from small tomato plants; remove or harvest lettuce before the tomato canopy closes and holds moisture on leaves overnight.
- Borage & tomatoesPair
Borage · Tomatoes
Borage flowers for bees; young leaves are edible (hairy texture). Self-seeds freely—place where volunteers are welcome.
- 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: tomato & fennelAvoid
Tomatoes · Fennel
Fennel can allelopathically stress some neighbors; tomatoes near vigorous fennel often look unhappy. Keep fennel in its own corner or container.
- Avoid: tight tomato + brassica spacingAvoid
Tomatoes · Broccoli / kale
Both are heavy feeders with big root systems; crammed together they compete for water and nutrients and reduce airflow.
- 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.