Nasturtiums are one of the most popular flowers for vegetable gardens, and for good reason. They're a colorful, beautiful addition to a vegetable patch and can help cover the soil, attract pollinators, trap pests, and improve yields for neighboring plants. Aside from being a useful companion plant, nasturtiums are also edible; they make a peppery addition to salads, pickles, and fermenting recipes.
This guide covers the many benefits of companion planting with nasturtiums, some of the vegetables, flowers, and herbs that grow best with them, and a few tips for herbs to avoid planting with nasturtiums.
Skip Ahead: Benefits of companion planting • Best companion plants for nasturtiums • What not to plant with nasturtiums
Benefits of companion planting with nasturtiums
Nasturtiums can benefit from being planted with a few herbs and flowers that repel pests, but it's more common that nasturtiums' companions will benefit from proximity to the flowers. Here's how planting nasturtiums in your vegetable garden can benefit other plants:
- Covering soil: Nasturtiums have a low-growing, spreading habit that make them highly effective at covering the soil, suppressing weeds, and preventing water loss.
- Improving soil condition: Paired with trellised vegetables, nasturtiums can aerate the soil, making it easier for companion plants to access water and nutrients.
- Deterring pests: Nasturtiums may help repel cucumber beetles. They'll also benefit from growing next to plants that repel their pests: aphids and nematodes.
- Reducing pest damage: Though nasturtiums don't repel many pests, they are a useful trap crop for nematodes and aphids. Planted a short distance from your veg, nasturtiums can lure these pests away and prevent infestations in more valued crops.
- Attracting pollinators: Bees and other pollinators love nasturtiums, which means that interplanting with nasturtiums can help improve yields in insect-pollinated plants.
The best companion plants for nasturtiums
Nasturtiums grow best in full sun and with regular watering. They produce the most flowers when planted into poor soils, but they'll still do well planted in rich soil next to heavy-feeding vegetables like cucumbers and tomatoes.
Here are a few vegetables, herbs, and flowers that grow well with nasturtiums:
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1. Peppers
Planting nasturtiums with your peppers can help repel whitefly and lure aphids away from pepper leaves. Nasturtiums also have a low-growing, spreading habit that shades the soil, allowing it to retain the moisture that peppers need.
Read More: The 13 Best Companion Plants for Peppers
2. Tomatoes
In addition to improving and shading the soil around tomato plants, nasturtiums can help with tomato pests. Companion planting tomatoes with nasturtiums can help reduce whitefly populations, or lure away nematodes and aphids.
If you use nasturtiums as a trap crop, allow them to become established before planting out your tomatoes and keep them a short distance away from the tomato plants. This encourages nematodes and aphids to colonize the nasturtiums, and it'll make it less likely that the pests wander over to the tomatoes.
Read More: How to Grow and Harvest Tomatoes
3. Cucumbers
Growing cucumbers with nasturtiums can help with whiteflies, aphids, and nematodes, but it may also help repel cucumber beetles.
Companion planting with nasturtiums can also keep the soil cool. Cucumbers need lots of moisture, so planting nasturtiums around the base of a cucumber trellis can help by shading the soil and preventing water loss.
Finally, nasturtiums attract pollinators that can help with pollination and, ultimately, yields.
Read More: The 15 Best Companion Plants for Cucumbers
4. Kale
Like other brassicas, kale attracts a variety of moths, worms, beetles, and soft-bodied pests. Nasturtiums won't help with all of them-- in fact, marigolds are a more effective companion plant for kale and cabbages. But nasturtiums will provide habitat for beneficial insects like ladybugs, which prey on some of those pests.
5. Broccoli
As a trap crop, nasturtiums can protect broccoli from aphids and nematodes. This can be especially helpful in the late summer and fall, when aphids can completely colonize brassica plants. Nasturtiums will also help suppress weeds around broccoli plants, which need generous spacing.
Read More: The 10 Best Companion Plants for Broccoli
6. Peas
Companion planting peas with nasturtiums can help improve pollination, suppress weeds, and improve soil condition. Peas grown up a trellis and underplanted with nasturtiums will benefit from the soil's improved moisture retention, as well as aerate the soil for pea roots.
7. Basil
Basil attracts beneficial insect predators like lacewings and ladybugs, which prey on nasturtium pests like aphids. If you want to plant nasturtium in your vegetable garden but are interested in harvesting its flowers, companion planting with basil could help.
Growing basil with tomatoes, marigolds, and nasturtium is a classic companion pairing. All of these plants grow well together, and between them will support predatory insects, attract pollinators, suppress weeds, repel pests, and attract pollinators.
8. Parsley
Parsley is a biennial herb that will grow through the summer, though it has a tendency to bolt when conditions are too hot or dry. Growing parsley with nasturtiums can help by keeping the soil cool and preventing water loss, and both plants will contribute to a biodiverse, healthy vegetable garden.
Read More: The Best and Worst Companion Plants for Parsley
9. Marigolds
Marigolds are the classic companion flower for vegetable gardens, thanks to their ability to repel a long list of garden pests. Marigolds and nasturtiums both like full sun and are tolerant of a variety of soils, so they're easy to grow together. Marigolds even have a nematicidal effect in the soil, which can protect nasturtiums and other nasturtium companions from root-knot nematodes.
Read More: The 16 Best Companion Plants for Marigolds
What not to plant with nasturtiums
Nasturtiums are a versatile companion flower, able to cope with the soil needs of many vegetables and herbs. These few exceptions are herbs with extreme growing requirements that aren't able to thrive alongside nasturtiums:
1. Mint
Mint is adaptable and eager to grow, but it has a tendency to spread quickly and choke out neighboring plants. While companion planting with mint can benefit some herbs and vegetables, it's almost always best done in a container.
2. Rosemary
While rosemary and nasturtiums both do well in full sun, rosemary thrives in very fast draining, poor soil. If planted into nasturtium's conditions, it would be more prone to fungal disease like downy mildew and produce less flavorful leaves.
Read More: The 11 Best Companion Plants for Rosemary
3. Sage
Like rosemary, sage grows best in fast draining soil with little nutrition. Planted with nasturtium, it's not likely to do its best. Instead, consider planting your sage into an herb bed or pot with rosemary, oregano, and thyme.
4. Cilantro
Cilantro is a cool weather plant that's quick to bolt at the first hint of summer heat. While it could theoretically do well next to nasturtiums, growing cilantro in the summer is a losing battle.