Companion planting with herbs means growing aromatic herbs next to vegetables and flowers to confuse pests, attract pollinators and predatory insects, and make better use of space. Classic pairings include basil with tomatoes, dill and fennel to attract hoverflies, chives with carrots, and nasturtiums as a sacrificial crop for aphids. Some pairings – such as fennel next to most vegetables – are best avoided.
Key takeaways
- Strong herb scents can mask the smell of host crops from pests such as carrot root fly.
- Umbellifers (dill, fennel, coriander) attract hoverflies and parasitic wasps that eat aphids.
- Nasturtiums act as a trap crop, drawing aphids and cabbage whites away from vegetables.
- Fennel is a poor companion for most plants; mint should always be contained.
- Evidence for many traditional pairings is anecdotal – the strongest science supports attracting beneficial insects.
How does companion planting work?
Companion planting draws on centuries of gardening tradition, and some of it is backed by research. The main mechanisms are:
- Scent masking: strongly aromatic herbs can make it harder for pests to find their target plants.
- Attracting beneficial insects: flowering herbs provide nectar and pollen for hoverflies, lacewings, ladybirds and parasitic wasps, whose larvae eat aphids and caterpillars.
- Trap cropping: some plants lure pests away from more valuable crops.
- Pollination: herb flowers bring bees to fruiting crops such as tomatoes, squash and beans.
- Space and shade: low herbs act as living mulch beneath taller crops.
Herb companion planting chart
| Herb | Good companions | Benefits | Keep away from |
|---|---|---|---|
| Basil | Tomatoes, peppers, asparagus | May deter whitefly and thrips; flowers attract bees | Rue, common sage |
| Chives | Carrots, roses, apples, tomatoes | Onion scent may deter carrot fly and aphids | Beans, peas |
| Dill | Brassicas, lettuce, cucumbers, onions | Attracts hoverflies and parasitic wasps | Carrots, fennel, tomatoes (mature dill) |
| Fennel | Best grown alone | Attracts beneficial insects | Most vegetables, dill, coriander |
| Mint | Cabbages, tomatoes (in pots) | Strong scent may deter flea beetles and cabbage moths | Parsley; plant only in containers |
| Rosemary | Beans, brassicas, carrots, sage | May deter carrot fly and cabbage moths | Basil, cucumbers (different water needs) |
| Sage | Brassicas, carrots, rosemary | Scent may confuse cabbage moths and carrot fly | Cucumbers, onions |
| Thyme | Brassicas, strawberries, aubergines | Ground cover; flowers attract bees | Few conflicts |
| Oregano | Most vegetables, especially brassicas and squash | Attracts pollinators and predatory insects | Few conflicts |
| Coriander | Spinach, potatoes, lettuce | Flowers attract hoverflies | Fennel |
| Nasturtium | Brassicas, beans, squash, fruit trees | Trap crop for aphids and caterpillars | Few conflicts |
| Calendula | Tomatoes, asparagus, most vegetables | Attracts hoverflies and bees | Few conflicts |
| Borage | Strawberries, tomatoes, squash | Major bee plant; improves pollination | Few conflicts |
The best herb pairings for popular crops
Tomatoes
Plant basil between tomato plants in greenhouses and beds. Studies suggest basil may reduce whitefly and thrips numbers, and it certainly makes the most of space. Add calendula and borage for pollinators.
Brassicas (cabbage, kale, broccoli)
Surround brassicas with aromatic sage, rosemary, thyme, dill and mint (in pots), and plant nasturtiums nearby as a decoy for cabbage white butterflies and aphids.
Carrots
Chives, rosemary and sage may help mask the smell of carrots from carrot root fly, the crop’s worst pest. Avoid planting dill and fennel near carrots, as they are in the same family and can share pests or cross-pollinate.
Strawberries
Thyme makes a neat border, and borage boosts pollination for better yields.
Roses
Chives and garlic are traditional companions said to reduce aphids and black spot. Lavender and catmint around roses attract pollinators and look beautiful.
Herbs to keep apart
- Fennel releases compounds that can inhibit the growth of many plants; give it its own spot.
- Dill and fennel cross-pollinate, producing poor-flavoured seed.
- Mint will overrun its neighbours unless contained – read how to grow mint.
- Mediterranean herbs and moisture lovers: rosemary and lavender like dry soil, while basil and parsley want regular water. Grouping plants by water needs matters more than folklore.
Does companion planting really work?
Research is mixed. Studies consistently show that flowering herbs increase beneficial insects, and intercropping can reduce some pest problems. Other claims, such as herbs “improving the flavour” of neighbouring vegetables, are largely anecdotal. Treat companion planting as one tool in an organic approach, alongside crop rotation, healthy soil, netting and good hygiene.
A simple companion bed layout
Try a 1.2 × 2.4 m (4 × 8 ft) raised bed: tomatoes along the back with basil between them, a row of lettuces and carrots in the middle edged with chives, and a front border of thyme, nasturtiums and calendula. For more ideas, see the 15 easiest herbs to grow.
Frequently asked questions
What herbs should be planted next to tomatoes?
Basil is the classic companion for tomatoes. Chives, parsley, calendula and borage also grow well alongside them and attract pollinators.
What herbs should not be planted together?
Keep fennel away from most plants, avoid planting dill and fennel together, and always contain mint. Separate herbs with very different water needs, such as rosemary and basil.
Which herbs repel pests naturally?
Strongly scented herbs such as rosemary, sage, mint, chives and thyme may help confuse pests. Nasturtiums lure aphids away as a trap crop.
Can I plant basil and rosemary together?
It is not ideal. Basil needs regular watering and rich soil, while rosemary prefers dry, poor soil. Grow them in separate containers.
Does companion planting actually work?
Research supports companion planting for attracting beneficial insects and some pest reduction, while many traditional claims remain anecdotal.
