While nasturtiums won’t ever harm their garden-mates, the benefits of these plants are well-suited for specific herbs and veggies in your garden. From their ability to repel certain pests to their weed-suppressing leaf canopy, nasturtiums earn a spot in any garden or container.
I’ve experimented with companion planting nasturtiums throughout my garden over the years with great benefit. But, if you like a little science with your gardening practice, pick up a copy of Plant Partners: Science-Based Companion Planting Strategies for the Vegetable Garden to read the evidence that supports the anecdotes.
1. Pumpkins and squash
Because nasturtiums can repel squash bugs and reduce the damage these insects do to your other crops, they are the perfect companion plant for squash and pumpkins.
Nasturtiums grow low to the ground and don’t develop deep roots, while squash and pumpkin plants develop deeper roots with larger shade-providing leaves.
Since nasturtiums do well with a bit of shade and don’t need as many nutrients as squash, this arrangement works out well for your crops and your nasturtiums.
Some other plants that grow well with nasturtiums, pumpkins, and squash include corn and radishes. Marigolds can also offer a second line of pest protection with these plants.
2. Nightshade plants, such as tomatoes, potatoes, and peppers
Nasturtiums make great companions for plants from the nightshade family since the flowers will keep aphids off of your crop plants.
Aphids prefer nasturtiums to most other vegetation, so if they infest your garden, they will gravitate toward your flowers. To eliminate the aphids, all you need to do is cut back your nasturtiums and dispose of them.
Nasturtiums also repel potato bugs, another of these plants’ most common pests.
4. Cucumbers and melons
Nasturtiums and cucumbers are the ideal pair of companion plants. Melons belong to the same family as squash and cucumbers, so they grow with nasturtiums just as well as these other crops.
Nasturtiums naturally repel many cucumber pests, such as cabbage loopers, squash beetles, striped and spotted cucumber beetles, and whiteflies.
As with squash and pumpkins, nasturtiums thrive in the partial shade offered by cucumber vines without consuming too much water or nutrients from the soil.
My favorite part about growing melons with nasturtiums is the ground cover these flowers provide. Melons need a lot of water to produce juicy fruits, so the more the nasturtium creeps along and covers the ground with its leaf canopy, the less I need to water during the summer heat.
With all the other pest-relieving and soil-saving benefits of nasturtiums, you couldn’t find a better companion for your cucumbers, cantaloupes, honeydew, and watermelons.
6. Lettuce and greens
Nasturtiums make an excellent companion for lettuce since they maintain soil moisture, repel beetles, and draw aphids away from your lettuce leaves. Lettuce is also a suitable companion for cucumbers, onions, and radishes.
An edible flower in your salad bed is an excellent option for gardeners with kids. Anything the kiddos happen to nibble on will be safe and tasty.
Nasturtiums and sunflowers, with their red, yellow, and orange blooms, make excellent companions for their complementary colors, growth habit, and ability to reduce pest pressure.
Nasturtiums create a dense canopy of foliage, shading the soil and suppressing weeds, which reduces competition for nutrient-hungry sunflowers. Trailing nasturtiums will happily climb the sunflower stalks, bringing their blooms to the perfect height for hummingbirds.
The flowers also protect sunflowers from pests like aphids because of their ability to be a trap crop, as mentioned previously. Pests such as aphids, whiteflies, and cucumber beetles will head to the nasturtium first, leaving your sunflowers alone.
8. Brassicas, such as cabbage, broccoli, cauliflower, and kale
Nasturtiums grow very well with plants from the Brassicaceae family, which includes some great garden plants like:
- Brussels Sprouts
These leafy greens are hardy enough to part patches of nasturtiums, providing shade to the flowers’ leaves.
However, pest control is the most significant advantage of planting nasturtiums with Brassicaceae. Nasturtiums repel these plants’ most prevalent pests, including cabbage worms and loopers, squash beetles, and whiteflies.
Nasturtiums are also more attractive to aphids than brassica plants, allowing you to use these flowers as a trap.
Other plants that grow well with these cruciferous vegetables and nasturtiums include sage, beets, corn, rosemary, spinach, and sunflowers.
Nasturtiums repel the most common pests of carrots, including carrot flies, squash bugs, and cucumber beetles.
However, nasturtiums also provide an excellent ground cover that retains moisture, which is critical when growing carrots. Carrots take a while to germinate, and keeping the soil moist during that time can be tricky.
The shade from the nasturtium leaves can help maintain moisture, just make sure the flowers don’t grow so thick that they block all the sun and prevent the carrot seeds from germinating.
Beans are nitrogen-fixating plants, and nasturtiums thrive in soils with excess nitrogen. Both crops enjoy full sun and regular water, so this pair is compatible in multiple ways.
Nasturtiums can be a valuable trap crop with beans to keep aphids away from your food crops.
When growing these plants together, opting for the dwarf varieties of nasturtiums is best, leaving plenty of trellis space for your beans to thrive and potentially keeping any aphids on a lower level than your bean plants.
However, if you only have climbing nasturtiums, you can still grow them up the same trellis as your beans, just watch out for aphids and prune infested nasturtium vines as necessary to keep your beans healthy.
Marigolds are one of the most popular and common flowers to use as companion plants, and luckily, they do very well when planted beside nasturtiums.
Marigolds are one of the most effective plants for controlling the growth of parasitic nematodes in your garden. So, planting them with your nasturtiums can give you an extra line of defense against pests.
Begonias often fall victim to whiteflies and aphids, but nasturtiums can keep these pests away. As I discussed in another companion planting article on this site, 13 Flowers And Herbs To Plant Together, nasturtiums and begonias also have similar growing needs.
Just like nasturtiums, begonias also have brilliant flowers that can add bright color to your garden. Try a salmon-red begonia mixed with a peach nasturtium for a happy flower bed.
Chives are easy-care, perennial herbs that will grow happily in pots and garden beds with little fuss. Chives require well-drained soil and full sunlight, which means they pair perfectly with nasturtiums.
As alliums, chives are particularly useful as companion plants when utilized for their natural pest-repelling properties. Even though nasturtiums are often used as a trap crop, if they are your valuable or prized crop, then try planting chives next to them for a dose of protection.
If you plant mint and nasturtium together, be prepared to have a garden bed that you’ll never plant in again.
I’m kidding. Sort of. Both nasturtiums and mint are wildly prolific plants. Mint spreads via rhizomes, which are roots that travel through the soil and pop up nearby to start a new plant. Nasturtiums propagate via seeds, of which they produce many that drop and germinate directly in the garden.
The two plants combined will easily and quickly take over any space you give them, so use this duo to cover empty ground or create a self-sufficient corner of the yard that you don’t need to maintain.
Can you tell I love companion planting? Here are a few more articles about combining plants in the garden.