What to Grow with Peppers

Peppers face consistent pest pressure. Aphids find them early in the season. Spider mites move in during hot, dry spells – exactly the conditions a rooftop or south-facing balcony creates through July and August.

Thrips damage developing fruit without being immediately visible. The right companion plants address all three, not by eliminating the pressure but by reducing it to a level the crop can handle without intervention.

The companion planting approach for peppers in containers works the same way as for any other pot-grown crop: adjacent pots rather than crowding companions into the same container.

A 10 to 15 litre pepper pot is fully occupied by one plant’s root system through the season. Companions go alongside, close enough for volatile compounds to carry and for beneficial insects to move between plants freely. Hot peppers and sweet peppers share the same companion needs, this guide applies to both.

Companions that deter pests from peppers

The pest pressure peppers face: aphids, thrips, spider mites, whitefly, is consistent and predictable. The companions below each target one or more of these pests through different mechanisms. None of them replace monitoring and intervention when a problem takes hold, but they reduce the frequency and severity of outbreaks.

Basil

Basil is the most natural companion for peppers in a container setup. It shares the same growing requirements almost exactly: 6 hours of sun minimum, warmth, consistent moisture, and protection from cold nights. Placing a pot of basil beside a pepper container requires no adjustment to either plant’s care routine.

The companion benefit comes from the volatile aromatic oils basil produces continuously through the growing season. These are observed to deter aphids and thrips from plants in their immediate vicinity.

The deterrence is proximity-based, which means the basil needs to be right beside the pepper, not a metre away across the rooftop. A 3 to 5 litre pot placed directly adjacent is the right setup.

Keep the basil harvested and pinched back. A bushy, actively growing basil plant produces more volatile oil than one that has flowered and slowed. The kitchen harvest and the companion benefit reinforce each other.

Full growing guide: How to grow basil in containers

Marigold

French marigold – Tagetes patula – brings the same benefits to peppers that it brings to tomatoes and cucumbers: root secretions that suppress soil nematode populations in surrounding compost, and flowers that attract hoverflies whose larvae predate aphids at a useful rate.

In a container setup, grow marigolds from seed six to eight weeks before pepper transplants go outside, so they’re already in flower when the season starts. One plant in a 10 to 15cm pot placed beside each pepper container is enough.

The nematode suppression works through the compost the roots share or sit adjacent to, and the hoverfly benefit extends across the whole growing area.

Oregano

Oregano is less commonly mentioned as a pepper companion than basil, but it earns its place. The aromatic compounds it produces are reported to deter aphids and spider mites. Two pests most likely to cause problems on peppers in a hot, dry rooftop environment are.

The evidence is observational rather than rigorously documented, but oregano is a useful kitchen herb in its own right, and the cost of growing it beside peppers is minimal.

One practical note: oregano is considerably more drought-tolerant than peppers. A pepper container needs consistent moisture through the fruiting stage; oregano prefers to dry out between waterings.

Putting them in the same pot creates a watering conflict. Keep oregano in its own 15cm pot placed adjacent – close enough for the aromatic benefit, managed independently for water.

Chives

Chives provide two benefits for peppers. Through the growing season, their allium compounds are reported to deter aphids from nearby plants – a lower-concentration version of the same mechanism attributed to garlic.

When they flower in early summer, the purple blooms attract pollinators in numbers that improve the rate of pepper flower visits, which directly improves fruit set.

This second benefit is worth noting because peppers are not as reliably self-pollinating as tomatoes. In a sheltered balcony or rooftop space with limited pollinator traffic, poor fruit set is a real problem. A pot of flowering chives beside the pepper container increases the pollinator presence in that specific area.

Companions that use space well around peppers

Pepper containers, like tomato grow bags, create usable microclimates around them that would otherwise go to waste. The plants below exploit the early-season window before the pepper reaches full size, and the space alongside the container once it does.

Spinach

Spinach and peppers are a practical seasonal pairing in a container setup. It is a cool-season crop that performs best in spring, exactly when pepper plants are young and not yet casting much shade. A shallow trough of spinach placed alongside a pepper container in early spring makes productive use of the space before the pepper needs it.

By the time the pepper has grown to its full canopy size in late spring and early summer, the spinach will have completed its harvest window and be ready to clear.

The two crops never genuinely compete because they occupy different seasons within the same growing year. The spinach trough can then be replanted with a heat-tolerant summer crop – basil, nasturtium, or a succession of radish – once it’s cleared.

Keep spinach in its own shallow trough of 15cm depth rather than the same pot as the pepper. Root competition in summer, even after the spinach is harvested, is not worth the risk.

Full growing guide: How to grow spinach in containers

Nasturtium

Nasturtium beside peppers works as a trap crop in the same way it does beside tomatoes and cucumbers – aphids find it more attractive than pepper foliage and colonise it first. This gives a visible early warning and a plant to manage before the problem reaches the pepper.

The monitoring requirement applies here too. A nasturtium with a small, stable aphid population is functioning correctly. One that’s overwhelmed – distorted leaves, heavy aphid mass, beginning to die back – needs to be removed before the aphids migrate.

In a rooftop container setup where everything is in close proximity, an unmanaged trap crop that collapses can deliver the aphid population directly to the crop it was meant to protect.

Place nasturtium in its own pot or a nearby railing planter. Check it every three or four days through the season.

Compatible neighbours for peppers

The most common question about pepper companions is whether peppers and tomatoes can be grown together. The answer is yes – they’re compatible neighbours.

Both need 6 to 8 hours of sun, both need consistent moisture and regular feeding, and neither produces compounds that inhibit the other. In a small rooftop or balcony space where both crops are being grown, placing them near each other is fine.

What they don’t do is actively benefit each other the way basil benefits both of them. Tomatoes and peppers share a similar pest profile – aphids, whitefly, spider mites find both attractive. Growing them together does not reduce that shared pressure; if anything, it concentrates it.

The practical framing is that tomatoes and peppers coexist comfortably but neither acts as a companion for the other in the pest-deterrent sense. Grow both, keep the actual pest-deterrent companions – basil, marigold, chives – between and around them.

What not to grow with peppers

Three plants belong away from peppers regardless of how convenient the placement might seem.

Fennel is allelopathic to peppers – it releases compounds from its roots and foliage that inhibit growth of nearby plants, including peppers. It provides no companion benefit in return and should be isolated from the rest of the growing space entirely.

On a rooftop where all containers are in close proximity, this means keeping fennel in a corner well away from the main growing area.

Brassicas – kale, broccoli, cabbage compete with peppers for the same nutrients without providing any deterrent or beneficial insect benefit in return. Brassica roots also release compounds that may interfere with pepper root development over time.

In a container setup where every pot position is a deliberate choice, a brassica next to a pepper is an opportunity cost: that space could hold a basil plant or a pot of chives that actively improves the pepper’s season.

Apricot trees are an unlikely neighbour on a rooftop but worth mentioning for growers with container fruit trees: apricots can harbour specific viral diseases that transfer to pepper plants through aphid vectors. The risk is real enough to keep any solanaceous crop pepper, tomato, aubergine away from apricot in a confined growing space.

A few final words

The companion setup that works best for a pepper container is straightforward and low-effort: basil in a pot directly beside it, a French marigold at the base, and chives nearby to flower through early summer.

Nasturtium in a railing planter adds the trap crop layer. That combination addresses aphids, thrips, nematodes, and pollination in one arrangement without requiring separate interventions for each.

For the full pepper growing picture, the chilli and hot pepper container guide covers the complete season. And for the companion planting principles that apply across all fruiting crops, the guide to growing with tomatoes covers the shared logic in more detail.