Best Companion Plants for Strawberries (And What to Avoid)
Discover the best companion plants for strawberries — with the science behind why they work. Boost yield, fight gray mold, and correct the marigold myth.
A strawberry bed planted with borage as a companion produced 70% fruit set in one university study — compared to just 45% in isolated beds. That gap isn’t luck. It’s the direct result of what’s growing alongside your plants.
Most companion planting guides give you a list. This one gives you the biology behind it — which plants genuinely help, why each one works at the chemical level, and two companion planting myths that even experienced gardeners repeat. You’ll also find a practical layout for arranging companions in your strawberry bed, and a clear table of what to plant, how close, and what to keep far away.
Why Companion Planting Matters for Strawberries Specifically
Unlike many fruiting plants, strawberries are almost entirely dependent on insect pollinators. Each strawberry flower contains around 80 pistils — tiny female structures, each of which needs a pollen grain to develop into a fertilized seed (achene). Achenes aren’t decorative: they’re what triggers the receptacle tissue around them to swell into the fruit you eat. Fewer pollinated achenes means a smaller, lighter, and often misshapen berry.
A global meta-analysis of strawberry production found that without animal pollination, average fruit weight drops by roughly 25% and plants produce 43% fewer fertilized achenes — both leading directly to the deformed berries gardeners blame on poor varieties or bad weather. The research estimated the economic value of pollinator services to strawberry farming at $5.36 billion per year globally.
This makes pollinator-attracting companions your highest-priority planting decision. But good companions also address gray mold (Botrytis cinerea, the most destructive strawberry disease), root-feeding nematodes, aphids, and weed pressure. The right combination handles several problems at once.
For a full overview of growing healthy strawberry plants from the ground up, see our complete Strawberry Growing Guide. For ideas on combining strawberries with the rest of your edible garden, the Companion Planting Guide covers cross-crop combinations by bed type.
Borage: The Best-Researched Companion for Strawberries
Borage (Borago officinalis) is the one strawberry companion with peer-reviewed yield data behind it. A 2020 study published in Ecological Entomology found that strawberries companion-planted with borage produced 35% more fruits and 32% greater yield by weight compared to uncompanioned controls. That’s not a marginal effect — it’s the difference between a productive patch and a mediocre one.
University of Minnesota Fruit Research confirmed the mechanism: strawberry yield and pollinator abundance both decline measurably with distance from the borage planting. In their trial at the West Central Research and Outreach Center in Morris, MN, plots more than 50 feet from borage showed significantly lower average berry weight. The borage patch attracted honeybees, bumblebees, syrphid flies, and metallic green sweat bees — all of which then worked the nearby strawberry flowers.
Why does borage work so well? The star-shaped blue flowers produce continuous nectar throughout the day at accessible depth — unlike tubular flowers that exclude many bee species. Borage blooms from early summer through first frost, overlapping with strawberry flowering periods, and self-seeds freely so a single planting establishes year-round coverage over time.
Practical notes: Borage grows 18–24 inches tall and spreads 12–18 inches wide. Plant it 12–18 inches from the bed edge so it doesn’t shade strawberry crowns directly. It can be grown at bed corners or in a strip alongside the planting. The young leaves and edible flowers are used in salads — an additional yield from the same plant.
Spacing: 12–18 inches from strawberry crowns. One borage plant per 2–3 feet of bed edge is sufficient; overcrowding reduces the flower density that makes borage valuable.
Creeping Thyme: Pest Deterrent and Living Mulch
Creeping thyme (Thymus serpyllum or T. praecox) does two distinct jobs in a strawberry bed, and most gardeners only know about one of them.
The first job is familiar: thyme deters pests. What’s less well known is the mechanism. Thyme releases thymol, a volatile monoterpenoid phenol that functions as a neurological disruptor for insects — specifically blocking acetylcholine neurotransmitter production at nerve synapses. This gives it repellent and feeding-deterrent properties against caterpillars, thrips, and spider mites. Thymol is also active against Botrytis cinerea, the fungal pathogen responsible for gray mold on strawberry fruits — the same disease garlic targets through a different pathway.
The second job is living mulch. A dense creeping thyme mat between strawberry rows shades the soil surface, suppressing weed germination without any chemical intervention. Research on living mulch systems shows they can reduce soil moisture evaporation by 40–55% through dense plant coverage — which matters for strawberries, which are shallow-rooted and drought-sensitive. The thyme also keeps the soil cooler during summer heat, reducing the fruit-drop and premature ripening that heat-stressed strawberries experience.
Unlike straw mulch, thyme doesn’t need replacing each season and won’t harbor slugs in the same way loose organic mulch can. Once established, it handles itself.
Best varieties for strawberry beds: Creeping thyme (T. serpyllum) or woolly thyme (T. pseudolanuginosus) — both stay low (under 3 inches) and spread horizontally without competing with strawberry crowns for vertical space.
Spacing: Plant every 6–8 inches within the bed. Full coverage takes one growing season. Thyme is drought-tolerant once established, so it doesn’t compete aggressively with strawberries for moisture.
Garlic and Chives: Antifungal Allies
Gray mold (Botrytis cinerea) is the single most common disease problem in home strawberry beds — it turns ripe fruits into gray-furred mush during cool, damp weather, and there’s no cure once it takes hold. Garlic and chives fight it before it starts, through allicin.
Allicin is the sulfur compound responsible for garlic’s pungent smell. Research published in Frontiers in Plant Science (PMC) found it to be the principal antifungal component in fresh garlic, capable of inhibiting Botrytis cinerea by disrupting the fungal cell wall — specifically by targeting cysteine residues in fungal proteins and diffusing directly through cell membranes. Minimum inhibitory concentrations of 1–5% were effective against multiple fungal strains in laboratory testing.
In a garden setting, garlic and chives release allicin and related sulfur volatiles continuously as their leaves brush and their roots interact with the soil. This creates a low-level antifungal atmosphere around neighboring plants — not a guaranteed cure, but a meaningful reduction in pathogen pressure, particularly for gray mold and fusarium species that affect strawberries in cool, wet seasons.
The above-ground benefit is aphid deterrence. Aphids, spider mites, and thrips are all sensitive to sulfurous volatile compounds and avoid planting areas where alliums are established. This is particularly relevant for June-bearing strawberry varieties in early spring when aphid pressure peaks alongside the first flush of runners.
How to use them: Plant garlic cloves in fall (October–November) around the strawberry bed perimeter for spring coverage — they’ll be established when aphid and Botrytis pressure begins. Chives can be interplanted between strawberry crowns at any time, spaced 4–6 inches apart. Both tolerate the same soil pH range as strawberries (5.5–6.5).
Spacing: Garlic: 6 inches from strawberry crowns. Chives: 4–6 inches, interplanted or as a dense bed border. Keep chives from flowering until late summer to prevent them from going to seed and crowding.
Quick-Win Companions: Bush Beans, Lettuce, and Spinach
Not every companion needs a complex mechanism to earn its place in the bed.
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→ Track My HarvestBush beans fix nitrogen in the soil through their symbiosis with Rhizobium bacteria in root nodules. Strawberries are moderate feeders that benefit from steady nitrogen availability, and planting bush beans in the rows between strawberry plants delivers that amendment without any additional fertilizing. Use bush beans specifically — pole beans grow tall enough to shade strawberry crowns in summer. Space at 6–8 inches from the nearest strawberry crown.
Lettuce and spinach earn their place as short-season gap fillers. They occupy the bare soil between strawberry rows in spring, reducing weed pressure through shading, and then bolt naturally as summer heats up — clearing space just as the strawberries reach peak production. Because they’re light feeders (low nitrogen demand), they don’t compete meaningfully with strawberries for nutrients. Their shallow roots avoid disturbing strawberry root systems. Harvest by late spring to give strawberry runners space to establish. Space at 6 inches between transplants.
Both of these companions reward beginners with edible returns from the same bed space while the strawberry plants are establishing — a practical advantage for gardeners learning how the system works.
What About Marigolds? Correcting a Common Myth
Nearly every companion planting article recommends marigolds as strawberry companions, usually citing nematode suppression. The advice is repeated so universally that it sounds settled. It isn’t.
According to research published by the University of Florida IFAS Extension, marigolds suppress nematodes through alpha-terthienyl — a compound described as “one of the most toxic naturally occurring compounds found to date” for nematode eggs. The catch: alpha-terthienyl is released only by active, living marigold roots directly in the soil, and it degrades rapidly when exposed to UV light. When marigolds are intercropped (planted alongside the target crop), the compound doesn’t reach the roots of neighboring plants in meaningful concentrations. The IFAS Extension explicitly states that marigold intercropped with susceptible crops “showed no effect on plant-parasitic nematodes” in the adjacent roots.
What does work: plant French marigolds (Tagetes patula) as a cover crop in the bed location two or more months before you plant strawberries. Till them in at the end of their season. The alpha-terthienyl then saturates the soil where your strawberry roots will actually grow. As a companion planted beside strawberries at the same time, marigolds provide color and some above-ground pest deterrence — but they won’t meaningfully suppress the nematodes in your strawberry bed.
If nematode pressure is your primary concern, choose resistant strawberry varieties (Allstar, Earliglow, Tribute) and use the marigold cover crop method the season before planting.
Companion Plant Quick-Reference Table
| Companion Plant | Key Benefit | Spacing from Strawberry | Watch Out For |
|---|---|---|---|
| Borage | Attracts pollinators; documented 35% more fruits (2020 study) | 12–18 inches from crown | Self-seeds vigorously — deadhead to control |
| Creeping Thyme | Living mulch; thymol deters pests; suppresses Botrytis | 6–8 inches, within bed | Slow to establish; needs 1 full season |
| Garlic | Allicin inhibits gray mold; deters aphids and spider mites | 6 inches from crown | Plant in fall for spring companion coverage |
| Chives | Same sulfur benefits as garlic; easier to maintain year-round | 4–6 inches, interplanted | Deadhead before seeds drop to prevent crowding |
| Bush Beans | Fixes nitrogen in root nodules — feeds strawberries for free | 6–8 inches | Use bush, not pole varieties (pole beans shade crowns) |
| Lettuce / Spinach | Fills gaps; suppresses weeds; harvests before peak season | 6 inches | Remove before runners need space (late spring) |
| Nasturtium | Trap crop for aphids; lures them away from strawberries | Bed perimeter only | Keep outside bed — vines reach 10 feet |
| Marigold (French) | Pre-season cover crop suppresses nematodes in soil | N/A — plant season before | Intercropping does NOT suppress nematodes (see above) |
Building a Strawberry Companion Planting Layout
Most gardeners treat companion planting as a random scatter of different plants. A more productive approach is to think in zones — placing each companion where its primary function is most needed.
Zone 1 — Bed perimeter (18+ inches out): Borage. This is where you want your main pollinator magnet — far enough that it doesn’t shade strawberry crowns, close enough that bees work from the borage flowers directly into the strawberry bed. Plant one borage at each corner of a raised bed, or every 3 feet along the long edges of an in-ground row.
Zone 2 — Bed edge (6–12 inches out): Garlic (planted in fall), chives (planted in spring), and nasturtiums. This creates a border of sulfur-releasing alliums that deter aphids before they can reach the crowns, with nasturtiums positioned to catch any aphids that pass through.
Zone 3 — Within the bed, between rows: Creeping thyme as a living mulch groundcover. Once established, it fills the spaces between rows that would otherwise host weeds, and its thymol volatiles diffuse upward through the bed canopy. Early in the season while thyme establishes, use lettuce or spinach as temporary gap-fillers in the same spaces.
Zone 4 — Row ends: Bush beans. Plant one or two bush bean plants at the ends of each strawberry row to fix nitrogen where the strawberry root zone runs deepest. Pull the beans after harvest and compost them to release stored nitrogen back into the soil.
This zoned approach means every square foot has a purpose. The outer ring handles pollinators and aphid interception, the inner zone handles ground-level pest and weed pressure, and the row ends add soil fertility.
If you’re growing blueberries nearby, note that many of the same companion principles apply — and blueberries share several good neighbors with strawberries, particularly alliums and thyme. Our Blueberry Growing Guide covers companion strategies for acidic-soil berry beds.
Plants to Avoid Near Strawberries — And the Real Reasons Why
Avoiding the wrong plants matters as much as choosing the right ones. Here’s what to keep away, and the actual mechanism behind each warning.
Tomatoes, peppers, potatoes, and eggplants (the nightshade family) share a common enemy with strawberries: Verticillium dahliae, the soil-borne fungus responsible for verticillium wilt. This pathogen infects approximately 300 host species and — critically — survives in soil for 25 years or more without a living host. According to Ohio State University Extension, growing any of these nightshade crops in the same soil as strawberries (even in alternating seasons) builds up pathogen load that will eventually devastate a strawberry planting. Keep all solanaceous crops in a completely separate bed rotation.
Fennel is one of the few genuinely allelopathic vegetables — it releases volatile compounds from its roots that inhibit the germination and root development of most neighboring plants, including strawberries. University of Illinois Extension describes allelopathic plants as creating a “growth no fly zone” around themselves through biochemical suppression. Fennel should grow in its own isolated bed.
Mint is a double problem: it’s invasive (runners can colonize an entire strawberry bed in one season) and it’s also a verticillium wilt host, appearing on the Ohio State Extension susceptibility list alongside tomatoes and peppers. If you grow mint near strawberries, you’re both competing for crown space and potentially inoculating your soil with the pathogen most destructive to strawberries.
Raspberries and other brambles share both verticillium wilt susceptibility and several viral diseases that transmit to strawberries via aphids. This is why commercial growers never plant the two in adjacent beds, and why old raspberry ground is typically rested for several years before strawberry establishment.
One myth worth busting: brassicas. Many companion planting guides list cabbage, broccoli, and Brussels sprouts as plants to avoid near strawberries. The research says the opposite — broccoli and Brussels sprout rotations have been shown to actually reduce verticillium wilt pathogen populations in California strawberry fields, making them a useful pre-season rotation crop rather than a neighbor to avoid.
Frequently Asked Questions
Can I plant strawberries and tomatoes in the same raised bed?
No. Both are susceptible to verticillium wilt, and the pathogen builds up in shared soil. Keep them in separate beds with independent soil that hasn’t hosted the other crop in the past five years.
Do I need all of these companions, or can I just pick one?
Borage alone will have the largest documented impact on yield. If you’re starting with one companion, start there. Add creeping thyme second — it handles weed and pest pressure passively once established. The rest add incremental benefits.
Will companion plants crowd out my strawberries?
Not if you respect spacing. Creeping thyme (6–8 inches) and chives (4–6 inches) are the most likely to encroach — monitor in the second year and trim edges. Borage, nasturtiums, and garlic should stay at bed edges where they don’t compete for crown space.
My strawberries are in containers — can I use these companions?
Yes, scaled down. Chives are the best container companion — plant two or three around the pot edge. A pot of borage nearby (or on an adjacent table) will still attract pollinators to your strawberry container. Creeping thyme works well in a large container as a ground cover beneath strawberry crowns.
When should I plant these companions relative to my strawberries?
Garlic: the previous fall. Creeping thyme: same time as strawberries in spring (it needs a full season to establish). Borage: spring, 2–3 weeks after last frost. Chives: spring, anytime after ground thaws. Lettuce and spinach: early spring, 4–6 weeks before last frost.
Key Takeaways
- Best overall companion: Borage — the only one with peer-reviewed yield improvement data. Keep it within 50 feet of your beds.
- Best pest and disease defense: Creeping thyme (thymol against Botrytis and insects) + garlic/chives (allicin against gray mold and aphids).
- Best soil improver: Bush beans — fixes nitrogen where strawberry roots need it most.
- Marigolds: Use as a pre-season cover crop, not as a companion. Intercropping doesn’t suppress nematodes.
- Avoid above all: Anything in the nightshade family (tomato, pepper, potato, eggplant), plus fennel, mint, and raspberries.
- Brassicas are fine: Broccoli and Brussels sprout rotations can actually reduce the verticillium wilt pathogen in your soil.
Sources
- Griffiths-Lee, J. et al. (2020). Companion planting to attract pollinators increases the yield and quality of strawberry fruit in gardens and allotments. Ecological Entomology. https://resjournals.onlinelibrary.wiley.com/doi/10.1111/een.12880
- Berries, Bees, and Borage — University of Minnesota Fruit Research
- Gudowska, A. et al. (2024). Pollinators enhance the production of a superior strawberry — A global review and meta-analysis. Agriculture, Ecosystems & Environment, 362. doi:10.1016/j.agee.2023.108815
- Impact of insect pollinators on yield and fruit quality of strawberry — NCBI PubMed Central
- Marigolds (Tagetes spp.) for Nematode Management — University of Florida IFAS Extension
- Garlic, from Remedy to Stimulant: Evaluation of Antifungal Potential — Frontiers in Plant Science (PMC)
- Verticillium Wilt of Strawberry — Ohio State University Extension
- Eliminating the Competition: Allelopathy in Plants — University of Illinois Extension
