Nasturtium Companion Plants: A Complete Guide
Nasturtium companion planting is one of those gardening strategies that sounds too good to be true — a pretty flower that also fights pests and feeds the soil? I was skeptical the first time I read about it. But after a few seasons of planting nasturtiums alongside my vegetables, I’m a full convert. These plants pull serious weight in the garden, and they’re ridiculously easy to grow on top of it all.
Attracting Beneficial Insects
One of the first things I noticed after planting nasturtiums was the buzz — literally. Bees and butterflies showed up in numbers I hadn’t seen before. Those bright orange and yellow flowers are basically neon “open for business” signs for pollinators, and since my vegetable garden is right next to where I grow them, everything got better pollination as a result. More tomatoes, more squash, more everything.
But it goes beyond pollination. Ladybugs and hoverflies love nasturtiums too, and those little predators eat aphids like it’s their job (because, well, it is). So you end up with this nice cycle: the flowers attract bugs that eat the bugs you don’t want. It’s one of those things that makes you appreciate how smart nature can be when you work with it instead of against it.
Repelling Harmful Pests
Nasturtiums produce these pungent oils — you can smell them if you crush a leaf — that a lot of garden pests can’t stand. Whiteflies, squash bugs, certain beetles… they tend to steer clear. I plant nasturtiums along the borders of my raised beds and I’ve noticed way fewer pest problems than when I didn’t. That’s anecdotal, sure, but I’m not the only gardener who’s seen this effect.
The strong scent seems to confuse pests trying to find their target crops by smell. If you’re trying to keep an organic garden (or just don’t want to spray stuff), nasturtiums are one of the best tools in the toolbox. I’d rather plant a few extra seeds than reach for a pesticide, and that approach has worked well for me so far.
Enhancing Plant Growth
Here’s something that surprised me: nasturtiums are actually good for the soil. They’re what’s called nutrient scavengers, pulling minerals up from deeper soil layers through their root systems. When the plants die back at the end of the season (or when I chop them and leave them as mulch), all those nutrients end up back in the topsoil where other plants can use them.
Their spreading, trailing habit works as living mulch too — shading the soil, keeping moisture in, and crowding out weeds. I had a patch where nasturtiums filled in under my tomato cages last year, and I barely had to weed that section all summer. The soil stayed cooler and moister than the bare areas nearby. That’s what makes nasturtiums endearing to us gardeners — they’re doing like five jobs at once and asking for almost nothing in return.
Pairing Nasturtiums with Vegetables
This is where it gets practical. Here are the pairings I’ve tried and the ones I keep coming back to:
- Tomatoes: Nasturtiums handle whitefly and aphid duty around tomatoes really well. The hoverflies they attract are voracious aphid eaters, and I’ve noticed cleaner tomato plants since I started interplanting them.
- Cucumbers: Cucumber beetles were the bane of my garden for years. Nasturtiums planted nearby seem to keep them confused and bring in predators that mop up the stragglers.
- Broccoli and Cabbage: Cabbage moths are relentless, but nasturtiums’ scent appears to throw them off. My brassicas have had noticeably less caterpillar damage since I added nasturtiums to those beds.
- Beans: Nasturtiums deter Mexican bean beetles and can even act as a sacrificial crop — the pests go after the nasturtiums first, leaving your beans alone. Smart, right?
- Radishes: Flea beetles love radish leaves. Nasturtiums seem to redirect them, drawing the beetles away from the radishes. My radish greens look way healthier with nasturtiums nearby.
Nasturtiums in Flower Gardens
Companion planting isn’t just for the veggie patch. I’ve worked nasturtiums into my perennial flower beds too, and they pull their weight there as well — both visually and functionally.
- Roses: Aphids on roses drive me crazy, and nasturtiums near the base of my rose bushes have helped. They attract the aphids to themselves (trap cropping) and bring in ladybugs to deal with the problem.
- Marigolds: Nasturtiums and marigolds together are like the pest-repelling dream team. Both produce compounds that pests dislike, and the color combination of orange, yellow, and red is genuinely stunning.
- Lavender: This pairing is more about aesthetics and pollinator support — the lavender brings in bees and the nasturtiums keep them around longer. Plus, the purple and orange color contrast is really striking in a border.
Troubleshooting and Considerations
I’d be lying if I said nasturtiums are completely problem-free. Aphids actually love them — that’s partly the point (trap cropping), but if populations get out of hand, you can end up with an aphid factory instead of an aphid diversion. Keep an eye on things and blast them off with a hose if colonies get too thick. I check mine weekly during peak aphid season.
Powdery mildew can be an issue in humid climates too. Give your nasturtiums enough space for air to circulate and don’t crowd them up against a wall or fence. If you spot mildew, pull those leaves off before it spreads — it’s a lot easier to manage early than once it’s everywhere.
One more thing that catches people off guard: nasturtiums prefer poor soil. I know that sounds wrong, but if you plant them in rich, heavily amended soil, you’ll get tons of beautiful leaves and barely any flowers. And it’s the flowers that do most of the pest-management work. So skip the fertilizer, plant them in average to lean soil, and don’t overwater. They’re tougher than they look and actually perform better when you leave them a little bit hungry.
Putting It All Together
Nasturtiums have earned a permanent spot in my garden. They’re cheap (seeds cost almost nothing), they grow fast, they look gorgeous, and they do legitimate work as companion plants. Whether you tuck them into vegetable beds or weave them through flower borders, they add value everywhere they go. Start with a packet of seeds next spring, scatter them where you need pest help or pollinator activity, and see what happens. From what I’ve seen, the results speak for themselves.
