Great Combos

  • Tomato + Basil for flavour and shared care.
  • Chilli + Marigold (tagetes) to pull pollinators and confuse pests.
  • Kale + Chives where aphids lurk.
  • Carrot + Spring onion to muddle carrot fly with onion scent.
  • Strawberry + Thyme for bee traffic and dry-loving partners.
  • French beans + Nasturtiums to lure aphids away and give edible flowers.

Things to Avoid

  • Overcrowding which blocks airflow and invites mildew.
  • Mismatched thirst like rosemary with basil.
  • Deep roots with shallow in tiny pots. They compete hard.
  • Tomatoes with potatoes in containers. Disease crossover and space clash.

Size beats theory: if a pairing looks cramped in your pot, split it. Healthy space is better than the “right” combo squashed in.

Pollinator Boost

  • Add edible flowers: nasturtiums, calendula, violas.
  • Let a few herbs bloom: basil, chives, oregano, thyme.
  • Keep sprays away. Use hand removal, water blasts, sticky cards first.

Container Pairings by Pot Size

Suggested plant pairings for common container sizes, with reasons and cautions.
PotPlant TogetherWhy it WorksSkip This
Window box (5–7 L) Parsley + Chives + Viola Shallow, frequent snips, bee-friendly faces for better fruit set around the garden. Tomato which is thirsty and top heavy for a box.
10–12 L Chilli + Basil or Salad mix + Radish Warmth lovers that share watering rhythm, or quick radishes under a cut-and-come-again canopy. Mint unless isolated. It spreads.
20 L Tomato (bush) + Basil + Marigold Classic trio. Flowers bring pollinators; basil shades soil and bumps flavour. Potato due to blight risk and sheer bulk.
40 L tub Courgette + Nasturtiums (edge) Nasturtiums trail, draw aphids, and you can eat the flowers. Big leaves cool the compost. Another courgette which overwhelms the tub.

Rule of thumb: If two plants enjoy the same sun and watering routine, they’re good candidates to share a pot.

Build Mini “Guilds” by Goal

Pest Deterrence

  • Brassicas + Chives/Garlic chives to discourage aphids.
  • Beans + Nasturtiums as a tasty decoy for aphids.
  • Lettuce + Dill for hoverflies which eat aphids.

Flavour & Yield

  • Tomato + Basil for richer fruit and shaded roots.
  • Strawberry + Thyme for better pollination and drier crowns.
  • Cucumber + Dill for pollinators and easy kitchen pairing.

Shade & Living Mulch

  • Chilli + Oregano where oregano drapes and cools the compost.
  • Courgette + Low nasturtiums to cover bare soil and reduce watering.

Nutrient Helpers

  • Peas/Beans + Leafy greens after the legume crop. Use the same tub, top up compost, and follow with salads.

Think in threes: a main crop, a helper herb or flower, and a small filler. If it feels crowded, omit the filler first.

Climate Notes (UK containers)

Cool or Windy Coasts / Far North

  • Pick compact, early varieties. Use fleece while hardening off.
  • Lean on hardy herbs and flowers: chives, parsley, calendula, violas.
  • Keep pots out of prevailing wind. Weight large tubs and stake early.

Milder South & City Heat Islands

  • Autumn-sow hardy annual flowers for very early spring colour near veg.
  • Watch for mildew in tight plantings. Give more spacing and water deeply less often.
  • Hot balconies suit chilli + basil, dwarf aubergine with thyme, and cucumbers with dill.

Microclimates matter more than the map. A sunny, sheltered wall can behave like it’s two zones warmer.

Rotation & Hygiene in Pots

  • Don’t grow tomatoes in the same tub two years running. Follow with salads or flowers and refresh a third of the mix.
  • Lift tired roots after harvest. Top up with fresh compost and a small handful of slow-release feed.
  • Wipe stakes and clips before re-using, especially after blight or mildew.

Healthy, well-spaced plants attract fewer problems than any single “magic” companion.