Harman UK

Tomatoes Companion Plants

Companion planting around tomatoes is a traditional way of mixing crops, herbs and flowers in a greenhouse, patio pots or a sunny bed. Evidence for direct pest control or bigger harvests is mixed, but varied planting can make efficient use of space and bring in pollinating insects. Keep good airflow and watering routines as the main priorities.

Good companions for Tomatoes

PlantWhy it helps
BasilTraditionally grown beside tomatoes in warm, sheltered places, basil shares similar watering needs and makes a useful edible companion.
French marigoldsTheir compact flowers may attract hoverflies and other beneficial insects, while adding colour around sunny tomato beds.
BorageBorage flowers can attract pollinating insects nearby, though it needs space and may shade smaller tomato plants.
Pot marigoldsPot marigolds provide long-lasting flowers that many gardeners use to increase insect activity around vegetable plots.
NasturtiumsNasturtiums are traditionally used nearby as a possible sacrificial trap for blackfly, though results vary between gardens.
Spring onionsSpring onions occupy little ground space and can be tucked between widely spaced tomatoes before the canopy fills.

Keep Tomatoes away from

PlantWhy to separate them
PotatoesBoth crops can be affected by blight, so separating them may make monitoring and removal of affected foliage simpler.
FennelFennel is often kept in its own corner because gardeners report it competing strongly with nearby crops.
CourgettesTheir large leaves can crowd tomato roots and reduce the airflow that tomatoes need in a humid British summer.

Tips

In the UK, plant tomatoes only after frost risk has passed and give each plant adequate room, especially under cover. Water at the base rather than wetting foliage, remove lower leaves only when necessary, and support plants well. Put flowers at bed edges or in nearby pots so they do not crowd roots or restrict ventilation.

Tomatoes companion planting: frequently asked questions

What are good companion plants for tomatoes?

Good companions for tomatoes include Basil, French marigolds, Borage, Pot marigolds, Nasturtiums, Spring onions.

What should you not plant near tomatoes?

Keep tomatoes away from Potatoes, Fennel, Courgettes.

How does companion planting help tomatoes?

Companion planting around tomatoes is a traditional way of mixing crops, herbs and flowers in a greenhouse, patio pots or a sunny bed.

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Companion planting is a traditional practice; results vary with your climate, soil and garden. Page updated 19 Sep 2026.