Companion planting often gets talked about as a veggie garden thing, but it can be just as useful in flower beds, cottage gardens, landscaped borders, and even pot plants on a patio.
How companion planting helps with pests
Most garden pests don’t show up by accident. They’re looking for particular scents, leaf shapes, and familiar plant groupings.
A garden bed full of one type of plant is easy for pests to find and easy to move through. A mixed bed is more confusing and often less appealing. Add in a few plants that attract beneficial insects, and you can dramatically reduce how quickly pests take over.
Companion plants tend to help in four main ways:
Scent and masking
Some plants release aromatic oils that make it harder for pests to locate their target plants.
Beneficial insect attraction
Many flowers provide nectar and pollen for ladybirds, lacewings, hoverflies and tiny parasitic wasps. These insects (or their larvae) feed on pests like aphids, whitefly and caterpillar eggs.
Trap planting
Some plants are so attractive to pests that they act as a decoy. Pests gather there instead of spreading through the rest of your garden bed.
Garden bed density
Filling gaps with low growers and flowers reduces bare soil and “landing pads”, making it harder for pests to settle and spread.
Flowers that attract beneficial insects (one of the most effective options)
These plants don’t necessarily repel pests directly. Instead, they attract the insects that eat pests – and this is often the most reliable long-term approach.
Sweet alyssum
Alyssum is one of the best companion plants for aphid control because it attracts hoverflies. Hoverfly larvae eat aphids in huge numbers. Alyssum is also brilliant for edging, filling gaps, and softening borders.
Yarrow (Achillea)
Yarrow is excellent for beneficial insects because its flat clusters of flowers make nectar easy to access, even for tiny predators. It also flowers for a long time and fits beautifully into cottage-style gardens.
Zinnias
Zinnias are one of the best “busy garden” plants. They attract a range of beneficial insects, flower heavily, and keep producing blooms if you deadhead them.
Cosmos
Cosmos is great for hoverflies and lacewings, and they’re also easy to grow. They’re ideal for gardeners who want something that looks relaxed and natural, rather than perfectly manicured.
Coreopsis
Coreopsis is hardy, long-flowering, and a steady pollinator favourite. It’s a great choice if you want companion plants that don’t need constant attention.
Gaillardia (blanket flower)
Gaillardia is another long-flowering plant that supports pollinators and beneficial insects. It’s particularly useful in sunny garden beds where you want colour without fuss.
Echinacea (coneflower)
Echinacea brings in pollinators during flowering and can attract birds later in the season. Birds are often overlooked in pest control, but they do help by feeding on insects and larvae.
Snapdragons
Snapdragons attract pollinators and add vertical height to garden beds. They’re especially useful in mixed borders where you want different flower shapes and levels.
Pansies and violas
These are especially useful in cooler months when many other flowers slow down. Keeping flowers in the garden across seasons helps beneficial insects stick around rather than disappearing until spring.
Flowers that help repel pests or reduce pest activity
These plants are often used because their scent, foliage, or natural chemistry makes them less appealing to pests, or makes it harder for pests to find nearby plants.
Lavender
Lavender is strongly scented, lasts a long time and is disliked by many pests. It’s also a bee magnet, which makes it useful in any garden where you want better pollination and more insect diversity.
Catmint (Nepeta)
Catmint has aromatic foliage and long-lasting flowers. It’s commonly planted with roses, partly because it supports beneficial insects and partly because it helps create a more confusing scent environment for pests.
Salvias (ornamental varieties)
Salvias are one of the best multi-purpose companion plants. They attract beneficial insects, support pollinators, and many have aromatic foliage. They also bring colour and height without being too delicate.
Society garlic (Tulbaghia)
Society garlic looks like a tidy landscaping plant, but it has a garlic-like scent that many pests dislike. It’s a great option for people who want a garden bed to look ornamental while still getting the pest-repelling benefits.
Pelargoniums (garden geraniums)
Pelargoniums are tough and strongly scented. They’re often used in garden beds and pots where people want fewer nuisance insects hanging around.
Chrysanthemums
Chrysanthemums contain natural compounds that insects dislike. They won’t magically stop every pest, but they can contribute to fewer ‘bad’ pests when mixed through beds.
Trap plants (the decoys that protect more delicate plants)
Trap plants are extremely useful in both ornamental and edible gardens, especially if you want to avoid sprays.
Nasturtiums
Nasturtiums are famous for attracting aphids. That’s exactly why they’re useful. Pests often gather on nasturtiums first, which can reduce pressure on other plants nearby. They also spill beautifully over edges and soften garden beds.
Calendula (pot marigold)
Calendula is another plant that aphids may prefer, which makes it useful as a decoy. It also attracts pollinators and beneficial insects, so it supports pest control in more than one way.
Petunias
Petunias can help discourage some pests, and they also fill space quickly, reducing bare soil and making it harder for pests to move around.
Here are a few practical examples that suit typical garden layouts.
Roses that don’t become pest magnets
Roses are one of the most common plants to suffer from aphids and sap-sucking pests. A helpful approach is to plant a mix of low flowers and aromatic companions around them.
A simple, effective combination is:
- Lavender or catmint nearby for scent
- Alyssum at the base to attract hoverflies
- Calendula or nasturtiums planted slightly away as trap plants
- Salvias in the same bed to bring in pollinators and beneficial insects
This creates a garden bed that looks lush and layered, while also making it harder for pests to dominate.
Mixed flowering borders that stay healthier
If you have a garden bed with shrubs and flowering plants, the easiest improvement is adding small pockets of companion flowers throughout, rather than planting them in one spot.
For example:
- Zinnias and cosmos for long flowering and pollinator support
- Marigolds and calendula for pest disruption and colour
- Alyssum along the edge to support hoverflies
This keeps the garden active, which is exactly what you want for natural pest control.
Pots and patio plants that support each other
Companion planting works beautifully in pots, and it’s one of the easiest places to try it because you can move plants around.
Some useful combinations include:
- Pelargoniums with petunias for scent and dense planting
- Lavender with alyssum for pollinators and beneficial insects
- Pansies and violas mixed with calendula in cooler months
A pot full of mixed flowers is not only prettier – it’s also less likely to be overrun by pests than a pot of one plant type.
Underplanting around citrus and fruit trees
Many fruit trees benefit from companion planting underneath them, because it increases insect diversity and reduces the “bare dirt” problem that often becomes dry and lifeless.
A good underplanting mix might include:
- Alyssum and calendula for beneficial insects
- Society garlic for scent-based pest disruption
- Lavender nearby to support pollinators
This helps create a healthier mini ecosystem around the tree.
What to avoid
There are also a few common mistakes that can make companion planting less effective
- Planting companion flowers in one corner instead of mixing them throughout
- Choosing plants that flower briefly, leaving beneficial insects with nothing to feed on
- Leaving large gaps of bare soil, which pests love
- Planting only one type of companion and expecting it to solve everything
The most effective gardens are mixed, layered, and full of continuous flowering.
The easiest way to start
If you want a simple formula that works without overthinking:
- Choose one aromatic plant (lavender, catmint, salvia, society garlic)
- Choose one beneficial insect flower (alyssum, yarrow, scabiosa, cosmos)
- Choose one trap or filler flower (nasturtium, calendula, marigold, petunia)
Then scatter them through your garden beds rather than grouping them together.
You’ll end up with a garden that looks fuller, flowers longer, attracts more beneficial insects, and is far less appealing to pests looking for an easy meal.
