Pest control in the garden: how companion planting is quietly changing what grows beside your vegetables

For gardeners looking for a gentler answer to pest pressure, pest control can begin with what is planted beside the crop. The idea behind companion planting is simple: place certain plants close together so they support one another, from masking scent to drawing in pollinators and beneficial insects.

What does companion planting do in a garden?

Companion planting is the practice of growing certain plants close together so they support one another. The support can be direct, such as strong scents that make it harder for pests to find a host plant, or indirect, such as flowers that draw in pollinators and beneficial insects that feed on aphids.

Russell Sharp, Founder of Eutrema, describes another layer of benefit: the method can also help with space, with taller crops creating light shade for smaller ones and ground-covering plants reducing bare soil, moisture loss and weeds. For gardeners trying to keep beds manageable, that can matter as much as the pest angle.

He adds that the main benefits are reduced pest pressure, steadier yields and more resilient growth with fewer interventions. In practice, that can mean fewer flare-ups and less reliance on sprays, especially when gardens are facing changeable weather.

Which plants are being used to deter pests?

Among the best-known options is French marigold. Mosh Latifi, co-owner of EcoCare Pest Management, calls it one of the most well-evidenced natural pest deterrents in the plant world. He says its roots release alpha-terthienyl, a compound that suppresses soil nematodes, while the scent of the foliage confuses and deters aphids and whiteflies above ground. He recommends planting them as a border around tomatoes or courgettes, where they can act as a first line of defence through the growing season.

Lavender is also highlighted for its aromatic oils, which repel certain insects while still attracting pollinators. Mosh says that for brassicas in particular, which are highly vulnerable to cabbage moths and aphid attack, a row of lavender planted alongside creates a scent barrier that disrupts the ability of pests to locate their host plants. It is a reminder that pest management does not always mean removing insects entirely; sometimes it means making a crop harder to find.

Nasturtiums take a different approach. Instead of repelling pests, they act as a sacrificial plant. Mosh explains that they attract aphids and blackfly so strongly that the pests colonise the nasturtium instead of nearby vegetables. Planted at the edges of vegetable beds, they can draw pressure away from crops, though heavily infested plants should be removed so pests do not migrate.

Which vegetables pair well with these plants?

The combinations highlighted for gardeners are practical rather than decorative. French marigolds are suggested near tomatoes, courgettes, beans and peppers. Lavender is presented as a useful companion for brassicas, including cabbage, broccoli and kale, as well as carrots. Nasturtiums are paired with broad beans, courgettes, cucumbers and brassicas.

The broader point is that companion planting is not a single trick but a system. Some plants disguise the scent of a crop. Some draw in insects that help keep aphids in check. Others absorb the pest pressure themselves. For gardeners trying to reduce inputs without complicating the layout of a bed, that flexibility is part of the appeal.

How are gardeners responding to fewer sprays and fewer losses?

The shift toward more sustainable gardening is shaping the way many people think about pest control, especially when they want an eco-friendly alternative to harsh pesticides. Companion planting fits that mood because it can be low effort and, in the words of the gardening guidance here, it will not damage other plants, especially edible ones.

That does not mean it solves everything. The advice also notes limits: some combinations should be avoided, particularly where one partner would need regular pesticide treatment that could drift onto the other plant. The approach works best when gardeners match the right plants to the right space and keep watching for changes through the season.

For now, the appeal is grounded in something modest but useful: a garden that asks less, gives a bit more back, and uses pest control as part of the planting plan rather than an emergency response. In that sense, pest management becomes less about fighting nature and more about arranging it with care.