Easy, Natural Pest Control: Let Your Herbs and Flowers Do the Work
Want to know something that will change how you think about your garden? You can fight bugs with flowers (companion planting); it’s natural pest control and one of the oldest tricks in the gardening book.
Not sure what companion planting is? It’s really nothing more than situating certain herbs and flowers near your vegetables to confuse pests, repel them outright, or draw in the beneficial insects that’ll take care of the bad ones for you.
It’s an approach we’ve been refining for years out here at Stoney Creek, and every season we’re more convinced it’s the direction home gardeners should be heading. Here’s what we’ve learned about which plants pull the most weight.
Plant Marigolds Everywhere
If you plant nothing else for pest control, plant marigolds. These cheerful, easy-to-grow flowers do a ton of work beneath the surface and above it. Aboveground, their strong scent actively repels whiteflies (those tiny, powdery insects that cluster on the undersides of leaves and weaken plants by sucking out their sap). Below ground, marigold roots release a natural compound that’s toxic to nematodes (microscopic worms that attack root systems).
Where should you plant them? Tuck marigolds throughout your vegetable beds, especially around tomatoes and peppers. Make sure to plant them in clusters rather than scattered singles. The scent needs some density to do its job. French marigolds tend to be the most effective for nematode suppression. They’re also just beautiful, which never hurts.
Basil Is Much More Than a Kitchen Herb
Basil is a culinary staple, but plant it near your tomatoes, and it becomes a bodyguard, too. The volatile oils in basil’s leaves are particularly effective at repelling tomato hornworms (the big, green-and-white-striped caterpillars that can strip a tomato plant overnight). They’re hard to spot and very destructive, and basil makes your tomato plants a much less appealing destination for them.
There’s an added benefit, too. Basil and tomatoes are natural kitchen companions, so growing them together makes sense from a garden-to-table perspective. You harvest both at the same time, from the same corner of the garden.
Lavender Is Beautiful, Fragrant, and Surprisingly Fierce
Lavender looks like pure decoration, but it earns its keep in a few ways that might surprise you. Moths despise it, which is important if you’re dealing with larvae that target your brassicas and leafy greens. It also repels fleas, which is useful if you’ve got animals moving through your property and into the house. Plus, its flowers attract pollinators and predatory wasps that prey on garden pests, so you’re getting pest suppression and pollination support from the same planting.
Plant lavender near pathways and along garden borders where it gets brushed against and releases its scent. It’s drought-tolerant once you get it established, which makes it low-maintenance (a lot of companion plants aren’t). Plant it once and let it do its thing for years.
Nasturtiums Protect Everything Else
Nasturtiums are what gardeners call a trap crop, and once you understand how they work, you’ll want them everywhere. Aphids absolutely love nasturtiums, and that’s exactly the point. You plant nasturtiums near your vulnerable vegetables, the aphids go for the nasturtiums instead, and your squash, beans, and cucumbers are left mostly alone. The idea here is that you’re giving the pests something they’d rather eat so they leave your food crops in peace.
Nasturtiums also repel squash bugs, which, if you’ve ever lost a squash plant to them, you know is no small thing. They’re fast-growing, edible (both the leaves and the flowers make a great addition to salads), and they reseed themselves pretty readily.
A Few Important Things to Remember
Companion planting works best when you think of it as a system rather than a one-time thing.
Mix It Up
Diversity is the point here. A garden with a lot of different plants close together is harder for pests to navigate and destroy than a monoculture of any single crop. Mix your herbs and flowers together in your beds rather than keeping them separate. Let things get a little layered and wild-looking.
Test Your Soil
Soil health matters, too, as any experienced gardener will tell you. Companion planting works best when your plants are healthy and strong to begin with, which means compost, good drainage, and not exhausting your beds season after season. A stressed plant is always more vulnerable to pest pressure, regardless of what’s growing next to it.
Track Your Results
Pay attention to what’s working. Keep notes, too. Write down in a notebook which pairings seemed to hold off the aphids, which areas had hornworm pressure anyway, and where the beneficial insects congregated. I recommend keeping one notebook per season. Just write the date on the cover and then break up the interior into your planting months. If you want more, you can make a spreadsheet on your PC or even invest in gardening software, but a paper notebook is a low-tech option that doesn’t come with any kind of subscription fee.
Want to Go Deeper?
If companion planting has you thinking more seriously about chemical-free growing, our Gardening Without Pesticides e-book is a great next step. It covers the full picture of organic pest and disease management in easy-to-understand language. Our goal was to create a garden reference book that you’ll actually reach for when something’s eating your bean plants.
Want to get your hands dirty alongside us in person? We’ve got several Canning 101 classes coming up this spring and early summer (in April, May, and June), where we’ll be working through everything from harvest to preservation. Growing food without chemicals doesn’t mean quite as much if you don’t know what to do with all those veggies when they arrive. Check the events page for dates and registration, and come spend a morning learning something that’ll serve you for the rest of your life.
