As summer heat intensifies and gardens burst into bloom, so do the bugs—some helpful, many harmful. If your vegetables are suddenly looking ragged or your tomatoes are under siege by aphids, it might be time to turn to a time-tested, natural solution: companion planting with herbs. This approach doesn’t just boost garden health—it can help you reduce or even eliminate the need for sprays or powders. And the best part? Many of the most beneficial herbs can still be sown from seed in summer and offer long-lasting benefits through the season.
Here’s how sowing dill, basil, cilantro, nasturtiums, and other summer-friendly herbs now can help protect your garden, encourage pollinators, and even improve the flavor of your crops.
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What Is Companion Planting?
Companion planting involves pairing crops together in ways that benefit one or both plants. These benefits can include pest control, improved pollination, enhanced flavor, or better growth. Herbs, in particular, are powerful allies thanks to their strong scents, nectar-rich flowers, and pest-repelling properties.
Why Sow Herbs in Summer?
Many herbs are fast-growing and can be direct-sown well into summer. Even if your early planting window has passed, there’s still plenty of time to get a crop of aromatic defenders in the ground. These herbs can grow quickly, flower before fall, and provide lasting protection to vulnerable vegetables.
Top Summer-Sown Herbs for Pest Control & Pollination
Dill
Repels: Aphids, cabbage loopers, squash bugs
Attracts: Lacewings, parasitic wasps, hoverflies
Dill is a magnet for beneficial predatory insects that prey on common garden pests. Its feathery foliage and umbels of yellow flowers draw lacewings and ladybugs like a beacon. Plant dill near cabbages, broccoli, squash, and tomatoes to help manage aphids and worms. Bonus: It’s also delicious in pickles and fish dishes!
Sowing Tip: Direct sow every 2–3 weeks through mid-summer for a continuous harvest and bug protection.
Basil
Repels: Thrips, mosquitoes, tomato hornworms, whiteflies
Improves: Tomato growth and flavor
Planting basil alongside tomatoes is one of the oldest garden pairings for good reason. Basil not only repels damaging insects but may also help tomatoes grow better and taste sweeter. Try interplanting Genovese basil in rows of tomatoes or around the base of pepper plants.
Sowing Tip: Basil thrives in heat—direct sow in well-drained soil and keep it pinched to encourage bushy growth.
Cilantro (Coriander)
Repels: Aphids, spider mites, potato beetles
Attracts: Parasitic wasps, hoverflies
Often overlooked once temperatures rise, cilantro can still be direct sown in summer—especially in partial shade or with frequent watering. Let it bolt and flower! The umbrella-shaped blooms attract a host of beneficial insects that feast on pests, while the roots help break up compacted soil.
Sowing Tip: For continuous pest control, sow every 2–3 weeks. In hot climates, aim for morning sun and afternoon shade.
Nasturtiums
Repels: Whiteflies, cucumber beetles, squash bugs
Traps: Aphids (sacrificial plant)
Attracts: Pollinators
A dual-purpose workhorse, nasturtiums not only brighten the garden with vivid blooms but also serve as decoys for aphids and other pests. Use them as “trap crops” near squash, cucumbers, or beans to lure pests away. They’re also edible—peppery leaves and flowers add spice to summer salads.
Sowing Tip: Direct sow now for blooms in 6–8 weeks. Sprawling varieties make good ground covers under taller crops.
Borage
Repels: Tomato hornworms, cabbage worms
Attracts: Bees, parasitic wasps
This fast-growing herb thrives in the heat and bursts with star-shaped blue flowers that bees absolutely love. Borage deters tomato hornworms and cabbage worms and improves the growth of strawberries, tomatoes, and squash. Its edible flowers are a bonus in drinks and salads.
Sowing Tip: Direct sow now—borage tolerates heat and dry conditions once established.
Chamomile (German)
Repels: Aphids, thrips, and whiteflies
Attracts: Hoverflies, parasitic wasps
Chamomile’s sweet-scented flowers aren’t just for tea—they bring in beneficial insects and improve nearby plant vigor. Often planted near brassicas and onions, it’s a calming addition to any bed.
Sowing Tip: German chamomile grows well from summer sowing if kept moist; prefers cooler evening temps to germinate.
Summer Savory
Repels: Bean beetles
Improves: Growth and flavor of beans and onions
A lesser-known hero in companion planting, summer savory protects beans from beetles while enhancing their growth. It also works well around onions and garlic. The flavor is similar to thyme, with a peppery kick.
Sowing Tip: Direct sow now or transplant starts for a quick-growing, low-maintenance herb.
Fennel (use cautiously)
Repels: Aphids, slugs, snails
Attracts: Swallowtail butterflies, parasitic wasps
Fennel is a beautiful, aromatic herb with towering flower umbels that attract beneficial insects. However, it can inhibit the growth of some vegetables (like beans and tomatoes), so plant it at the edge of the garden or in containers.
Sowing Tip: Best grown on its own or in pollinator strips—direct sow in full sun.
Lemon Balm
Repels: Mosquitoes, gnats
Attracts: Bees and hoverflies
This lemony member of the mint family is excellent for borders or partial-shade areas. Its flowers feed beneficial insects, while the leaves repel flying pests. Great for teas and fresh garnishes.
Sowing Tip: Sow in summer in part shade. Thin aggressively—lemon balm spreads quickly.
Mint (Spearmint, Peppermint)
Repels: Ants, aphids, flea beetles, cabbage moths
Mint’s strong scent confuses pests and deters them from brassicas, tomatoes, and beans. However, it spreads aggressively, so grow it in containers or isolated beds.
Sowing Tip: Sow in a separate space or pot. Water well during establishment.
Companion Planting Strategies
- Ring your crops. Plant herbs like basil or dill in a circle or border around tomatoes, peppers, or beans to form a natural pest barrier.
- Interplant rows. Alternate rows of herbs and vegetables to confuse pests and encourage beneficial insect movement throughout the bed.
- Use vertical space. Let herbs like nasturtiums trail from containers or up short trellises near your vegetables.
- Succession sow. Stagger your sowing dates to maintain a steady supply of young herbs and continuous flowering, which keeps the insect population in check.
Herbs for Pollinator Power
Beyond pest control, flowering herbs are some of the most effective pollinator attractors you can grow. Bees, butterflies, and hoverflies flock to dill, cilantro, borage, chamomile, and nasturtium blooms, improving fruit set in everything from squash to cucumbers.
Final Thoughts: Natural Defense, Beautiful Results
By tucking herbs into your garden now, you’re not just fending off pests—you’re building a more resilient, balanced ecosystem. These plants work hard to defend your crops, attract allies, and add flavor to your meals.
Whether you’re planting a second round of basil, starting dill for pickles, or adding nasturtiums as a splash of color, there’s still time to sow. Shop our selection of heirloom herb seeds today and give your garden the summer boost it deserves—naturally.
What are your thoughts? Drop a comment below!
FAQ:
Can I really start herbs in the middle of summer?
Yes! Many herbs like basil, dill, cilantro, and nasturtiums thrive in summer heat and grow quickly. With consistent watering and sun, you’ll still get good harvests and strong pest control benefits.
How close should I plant herbs to my vegetables for companion planting to work?
You can interplant them in the same bed, alternate rows, or surround your vegetables with herbs as a border. The key is proximity—scent, pollinator attraction, and pest confusion work best when herbs are nearby.
Which herbs are best for deterring aphids?
Dill, cilantro, and nasturtiums are especially effective against aphids. Nasturtiums often serve as a “trap crop,” drawing aphids away from more valuable plants.
Will these herbs grow well in containers?
Absolutely. Most of these herbs—including basil, mint, lemon balm, and nasturtiums—do great in pots. Just make sure they get plenty of sun and water, and that mint has its own container to prevent spreading.
Can I mix all these herbs together in one bed?
Some can be grown together, but others—like fennel and mint—should be isolated. Always check for compatibility; for example, basil and dill shouldn’t be grown close to carrots or each other when mature.
Do I have to let herbs flower to get the pest-control benefits?
In many cases, yes. Herbs like dill, cilantro, chamomile, and borage are most effective at attracting beneficial insects once they flower. For basil, frequent pinching delays flowering but still provides strong scent-based repellent properties.
What’s the best way to water herbs during summer heat?
Water deeply but less frequently to encourage strong roots. Mulch around plants to retain moisture and reduce stress. Most herbs prefer well-drained soil, so avoid soggy conditions.
Are any of these herbs perennial?
Some herbs like mint, lemon balm, and chamomile (in some climates) can come back each year. Others like basil, dill, cilantro, and borage are typically grown as annuals.
Can companion herbs improve vegetable flavor or yield?
Yes—basil is famously said to improve tomato flavor and growth. Summer savory benefits beans, while dill and cilantro help create a healthier, more balanced growing environment that leads to better yields.
Where can I buy seeds for all these herbs?
You can find heirloom, open-pollinated seeds for all these herbs right here in our shop. We carry high-quality varieties suited for home gardens, all ready to sow this season.
