9 Flowers That Make Great Companion Plants: Pest Control, Pollinators, and the Science Behind Each Pairing
Quick Reference: 9 Companion Plant Flowers
- Strongest evidence (UMN Extension): nasturtiums trap aphids off brassicas; sunflowers shade brassicas; marigolds suppress root nematodes (only the right species).
- For pollinators: calendula, alyssum, borage, lavender. All bring bees and beneficial insects within 1 to 2 weeks of bloom.
- For visual + pest mix: petunias, dahlias.
- Universal rule: plant flowers IN the bed, not just around it. Mixed plantings outperform border plantings on every measure.
- Tool: the Almanac’s main companion planting guide for the full system.
On this page
Flowers in a vegetable garden are not decorative. They are the trap crops, pollinator magnets, beneficial-insect harbors, and shade providers that decide whether your tomatoes, brassicas, and peppers thrive or get eaten. This guide is the 9 flowers UMN Extension and the Xerces Society both recommend for working pairs in the home garden, what each one actually does, and the evidence (where it exists) for the claims.
How Companion Flowers Actually Work (4 Mechanisms)
Per UMN Extension’s companion-planting research, flowers earn their space through four mechanisms.
- Trap cropping. Nasturtiums draw aphids off brassicas and tomatoes. The flowers become the aphid magnet, sparing the food crop.
- Pollinator attraction. Calendula, borage, alyssum, lavender pull bees and beneficial wasps into the bed.
- Shade and microclimate. Sunflowers shade cool-season brassicas through July heat, extending the harvest.
- Pest confusion. Diverse plantings with varying scents (marigold, dahlia, petunia) disrupt the olfactory navigation of insect pests.
The Marigold Question (What the Research Actually Supports)
Marigolds are the most-cited companion flower, with mixed evidence per UMN’s review.
- Root-knot nematode suppression (supported). Tagetes patula (French marigold) releases alpha-terthienyl from roots, killing root-knot nematodes. Requires interplanting for 2+ months, not casual scattering.
- Colorado potato beetle deterrent (NOT supported). Multiple field studies show marigolds do not reduce CPB damage on potatoes despite the folkloric claim.
- Flea beetle deterrent (mixed). Some evidence in brassicas; varies by region.
- General pest confusion (supported). Marigolds contribute to overall pest pressure reduction in mixed plantings.
9 Flower Companion Plant Pairings (Detail)
Below are the original 4 reasons to plant flowers near vegetables plus the 9 detailed pairings.
1) Flowers And Herbs Repel Garden Pests
Marigold flowers are known to keep a variety of garden pests at bay. Have problematic aphids in your garden? Try planting garlic, leeks, and chives nearby. These plants naturally repel aphids. Other aphid repellants include catnip, dill, cilantro, and fennel. Slug repelling herbs include chives, garlic, mint, lavender, fennel, anise, wormwood, rue, and rosemary.
2) Flowers Provide Important Shade
Planting tall or vining trellised flowers may provide important partial shade for vegetables that prefer cooler temperatures. Sturdy, tall flowers may also add support to vegetables in your garden.
3) Add To Visual Interest and Appeal
Combining a variety of plant colors, shapes and sizes, layers, and textures together gives your garden a unique, artistic style that doesn’t occur when each is isolated in beds or rows. Imagine a charming cottage garden bursting with color and romanticism.
4) Attract Pollinators
Dense bursts of color attracts beneficial pollinators such as hummingbirds, butterflies, and moths to your plants. Some flowers produce more pollen than others. Wise gardeners pair those that don’t attract bees along with those that do.
Red Roses With Lavender, Attracts Bees
Did you know that bees can’t see the color red? Thus, red rose varieties tend to attract less bees. Help these essential pollinators by planting lavender nearby. Bees are most attracted to the colors purple and blue love lavender nectar love lavender nectar, so, so plant lavender nearby. This may lead to abundant, healthy blooms.
Lavender is a superb companion for roses as it produces nectar which attracts bees and has similar soil and sun requirements. Lavender will not soak up all the nutrients or water. Another bonus, lavender suppresses weed growth and will grow to a height to conceal the lower cane portion of rose bushes. Plus, fresh cut roses and lavender make a lovely bouquet!
Calla Lilies and Catmint, Repels Aphids
Calla Lilies are gorgeous, elegant flowers grown from rhizomes. Yet i’ts prone to aphid infestation. Catmint (not to be confused with catnip) is a lovely perennial herb with lavender-blue flowers and grayish-green leaves. The aromatic catmint doubles as a pest repellant, deterring aphids and other garden pests from ruining your calla lilies.
Catmint is easy to grow and low maintenance. Both plants prefer full sun, or partial shade in warmer climates. Plant calla lily rhizomes outdoors in spring, after the last spring frost. Fill in the empty spaces between calla lily plants with catmint. The shallow root system of catmint plants will not interfere with calla lilies.
Pansies and Parsley, Edible Landscaping!
Grow pansies and parsley together for edible garnishes and other culinary uses. Pansies are popular annuals that yield stunning, colorful low-growing flowers. The lacy green leaves of the parsley plant pair well with the lovely pansy. Plant both plants outdoors in early spring, where they’ll receive six hours of full sun daily. Pansies can also be planted in the fall.
Larkspur and Yarrow, Repels Slugs And Snails
The lovely larkspur is a cottage garden classic grown for its tall, cut flowers. Slugs and snails love dining on larkspur. Yarrow is a lovely flowering perennial herb that naturally repels slugs and snails.
Plant a border of yarrow around larkspur or between rows to keep these garden pests away from the larkspur flowers. As a companion plant, the tall yarrow flowering herb companion plant will also add support and structure to larkspur as it increases in height.
Dahlias and Rosemary, Repels Snails
Snails are known to feed on young dahlia leaves. Planting a strong-smelling herb that repels snails and other pests such as rosemary around or between dahlias protects the young plant from damage, so it matures and yields beautiful blooms you’ll love.
Sunflowers and Broccoli, Provides Shade For Brassica Veggies
When planted together, sunflowers add bursts of color and height to your garden, while providing partial shade to brassicas vegetables such as broccoli, Brussels sprouts, cabbage, and cauliflower. Broccoli and other brassicas vegetables prefer growing in cool weather. Sunflowers also attract lots of bees to help pollinate your vegetables. And then there’s a crop of edible seeds to harvest from the sunflower heads.
Daffodils and Lettuce, Keeps Rabbits And Deer Away
Daffodils contain a poisonous substance called lycorine that deer and rabbits avoid ingesting. Daffodils are an easy to grow, pretty spring-flowering bulb. They should be planted in the fall, several weeks before the ground freezes.
Daffodils thrive in full sun. Plant bulbs in a protective border around a lettuce bed to keep rabbits out of the vegetable garden. Lettuce is a favorite garden food of rabbits and deer. Lettuce is a cool weather vegetable, planted in early spring and/or fall. Although it grows best in full sun, early on, as the weather warms, partial shade keeps it thriving longer. The partial shade from the daffodils may help extend your lettuce growing season.
Nasturtiums and Bell Peppers, Attracts Hummingbirds
Nasturtiums add bright yellow-red color as it carpets your garden bed. This lovely ground cover reduces the need to weed around these nightshade plants: bell pepper, tomato, and eggplants. Nasturtium thrives well in full or partial sun. The entire plant is edible, and tastes peppery, like watercress. It’s often used in salads. Its super sweet nectar (sucrose) attracts hummingbirds and other pollinators.
Petunias and Tomatoes, Nature’s Pesticide
Did you know that pretty petunias act as a natural pesticide when planted in vegetable gardens? This popular perennial known for its abundant, colorful trumpet shaped flowers emits a chemical in the air that repels many pests including aphids, squash bugs, leafhoppers, asparagus beetles and tomato hornworms.
Petunias are the perfect protective companion when planted near tomatoes and other vegetables in your garden. Plant petunias and tomato plants outdoors in late spring or early summer in a sunny location.
Companion Plant Flowers FAQ
What flowers are best for a vegetable garden?
Nasturtiums (aphid trap), French marigolds (nematode suppression), sunflowers (shade brassicas), calendula and borage (pollinator + beneficial-insect magnets), alyssum (ground-cover pollinator), and lavender (border pollinator). The 9 covered above are the most-recommended by UMN Extension.
Do marigolds really repel pests?
Some pests, not all. French marigold (Tagetes patula) is evidence-supported for root-knot nematode suppression when interplanted for 2+ months. The folkloric claim that marigolds repel Colorado potato beetles is NOT supported by controlled studies. Treat marigolds as one component of a diverse planting, not a single-pest solution.
What flowers attract pollinators to vegetables?
Calendula, alyssum, borage, lavender, and salvia attract the widest range of bees and beneficial wasps. Bee balm (Monarda) attracts hummingbirds and hummingbird moths. Sunflowers attract honey bees and bumble bees. Plant in clumps of 5+ rather than scattered singles.
Are there flowers that should NOT be planted with vegetables?
Avoid invasive non-native flowers (some Lonicera honeysuckles, butterfly bush in certain states). Avoid highly competitive perennials in the bed itself (mint will overtake everything). Avoid flowers that share pests with your vegetables (some petunias share aphid susceptibility with tomatoes).
How many flowers should I plant in a vegetable bed?
Per UMN research, aim for at least 3 flower species per 100 square feet of bed, blooming across overlapping windows from early spring to late fall. The diversity matters more than the absolute count.
Do companion flowers improve vegetable yield?
In mixed plantings yes, modestly but measurably. UMN trials find pest-pressure reduction translates to roughly 10 to 25 percent yield improvement on susceptible crops (brassicas, tomatoes). The bigger benefit is reduced spray needs and increased pollinator activity.
Deborah Tukua
Deborah Tukua is a natural living, healthy lifestyle writer and author of 7 non-fiction books, including Pearls of Garden Wisdom: Time-Saving Tips and Techniques from a Country Home, Pearls of Country Wisdom: Hints from a Small Town on Keeping Garden and Home, and Naturally Sweet Blender Treats. Tukua has been a writer for the Farmers' Almanac since 2004.
- Deborah Tukua
- Deborah Tukua
- Deborah Tukua
- Deborah Tukua
What is a strawberry companion?
Allisum around my tomatoes
The article mentions that petunias emit a chemical into the air that repels many insects. Can you identify it please?