A nasturtium does not behave like a polite border annual. It sprawls, loops, leans over timber, climbs if you help it, and drops bright flowers into the vegetable garden as if the lettuces and beans were waiting for punctuation. That informality is part of its usefulness. The plant softens hard edges, feeds the eye, feeds the table, and quietly makes a vegetable bed feel more alive.
Nasturtiums are often sold as edible flowers, but that phrase can make them sound like garnish and little else. In practice, they are working annuals. North Carolina Extension notes that the leaves, buds, flowers, pods, and seeds of Tropaeolum majus are edible, with a spicy, peppery taste, and that flowers add color to salads while seeds can be used like capers.1 A plant that can be border, bloom, herb, salad green, container spiller, and pollinator lure deserves more respect than a decorative sprinkle.
The trick is to place it where its looseness becomes structure. Nasturtiums are not tidy by nature. They are useful because they are generous.
Why the edge is the best place
The best place for a nasturtium is often not the middle of a bed but the seam between bed and path, pot and air, wall and soil. Wisconsin Horticulture describes compact forms as useful for edging, while trailing types can spill from hanging baskets, window boxes, walls, or act as groundcover.2 That habit makes them especially valuable in small gardens, where every edge is an opportunity.
Let a mounding variety mark the front of a herb bed. Let a trailing one slide down the outside of a raised bed, where it will not smother young carrots. Train a longer type loosely up a low bamboo support near beans or tomatoes. In containers, use nasturtium as the edible spiller beneath upright herbs such as basil, parsley, or dill.
This is garden design at a practical scale. The round leaves cover bare soil, the flowers pull warm color through a planting, and the soft stems hide the awkward geometry of boxes and pots. A vegetable bed can look productive and still have rhythm.
Grow them a little hungry
Nasturtiums are one of those plants that can become less charming when treated too richly. The Royal Horticultural Society recommends poor, well-drained soil in full sun, noting that rich soil encourages foliage at the expense of flowers.3 North Carolina Extension gives similar guidance, warning that fertilization can lead to more leaves and fewer blooms.4
That does not mean they want abuse. They still need water while establishing, and container plants dry quickly in May wind. But they do not need the richest compost in the garden or a regular feed. If your nasturtiums are lush, dark, and flowerless, the soil may simply be too generous. Move the next sowing to a leaner place, or stop feeding the container and let the plant remember why it makes flowers.
Sow after the danger of frost has passed, or start them in plantable pots if your season is short. Their large seeds are easy to handle, and Wisconsin Horticulture notes that soaking them for a few hours or overnight can improve germination.2 They resent root disturbance, so if you start them indoors, transplant gently and early.
Eating the leaves, flowers, and pods
The flavor is easiest to understand if you think of watercress or arugula: green, peppery, and slightly sharp. University of Minnesota Extension lists nasturtium flowers and leaves as edible and peppery, best used fresh in salads.5 The flowers are usually milder than the leaves, which makes them more flexible at the table. Young leaves can be torn into salads, tucked into sandwiches, or chopped into soft cheese. Flowers can be scattered over potatoes, eggs, pasta, cold soups, and anything that benefits from color and bite.
Seed pods are a different pleasure. Picked green and young, they can be brined or pickled into a caper-like condiment. They will not become true capers, which come from Capparis spinosa, but they bring a similar salty, pungent pop to a plate.
The usual edible-flower cautions matter here. University of Minnesota Extension advises choosing only flowers that are safe to eat, avoiding harmful chemical treatments, confirming the correct plant identity, and trying new edible flowers in small amounts.5 Grow your own from seed when you can. Do not eat flowers from roadsides, florist buckets, or garden-center plants unless you know they were produced for edible use and have not been treated with systemic pesticides.
What they can do for pests
Nasturtiums have a reputation as companion plants, and this is where it is worth being precise. They are not a force field. They will not make aphids, cabbageworms, or whiteflies vanish from a garden. North Carolina Extension lists aphids, mealybugs, and whiteflies among possible problems on Tropaeolum majus.1 Wisconsin Horticulture also notes aphids and imported cabbageworm caterpillars as common pests.2
That does not make the plant less useful. It means its usefulness is ecological rather than magical. If aphids collect on nasturtium leaves, you may notice them before they build heavily elsewhere. You can pinch off the worst leaves, rinse the plant with water, or let the patch act as a small monitoring station. The Royal Horticultural Society frames companion planting more broadly: insect-friendly flowers, including nasturtiums, are often grown near vegetables in the hope of supporting beneficial insects, and mixed plant communities can be more resilient than simple ones.6
So plant nasturtiums for diversity, observation, nectar, cover, and beauty. If they also distract a few aphids from a young bean shoot, accept the favor. Just do not let the folklore outrun your eyes.
A few varieties, many habits
The word nasturtium covers plants that can behave quite differently. Some are compact and mound neatly around a pot. Some trail several feet. Some are sold as climbing types, though Wisconsin Horticulture points out that trailing nasturtiums lack tendrils and do not climb well without help.2 That small detail matters. A nasturtium can be guided, tied, or leaned through a support, but it is not a pea.
For containers and crisp edges, choose bush or dwarf types. For walls, window boxes, and raised beds, choose trailing forms. Variegated varieties add interest even before bloom, especially in mixed edible containers. Deep red varieties look handsome near purple basil and bronze fennel. Yellow and orange flowers wake up blue-green cabbages and silver-leaved herbs.
If you want the plant for the kitchen, grow more than one. Harvesting flowers encourages more bloom, but a single plant can look sparse if every bright blossom becomes lunch. A small group lets you eat and still leave enough color for the garden.
Keeping them generous
Nasturtiums are not demanding, but they respond to attention. Pick flowers often. Remove yellowing leaves. Trim back stems that begin to bury neighboring seedlings. Water containers before they wilt hard. In hot climates, afternoon shade can help the plant carry on through summer, though flowering is usually strongest with good light.
Let a few seed pods mature if you want volunteers or seed to save, but remember that self-sowing can become messy in mild climates. North Carolina Extension notes that self-seeding can cause the plant to spread.1 In colder gardens, the occasional volunteer is often welcome. In warmer areas, treat seed drop as a choice rather than an accident.
Useful nasturtium supplies
- Seed Needs Jewel Mix nasturtium seeds: a straightforward seed mix for growing edible flowers in beds, containers, and border edges.
- Fiskars micro-tip pruning snips: useful for cleanly harvesting flowers, trimming soft stems, and removing aphid-covered leaves without tearing the plant apart.
- Avalution small bamboo trellises: helpful for guiding trailing nasturtiums in containers or along the edge of a raised bed.
Final thoughts
Nasturtiums are easy to underestimate because they are easy to grow. Their seeds are large, their flowers are cheerful, and their habit is relaxed. But that ease hides a clever garden role. They turn unused edges into edible color. They make containers feel abundant. They invite closer looking at leaves, flowers, pests, and pollinators.
Grow them where they can spill. Feed them less than you think. Pick them often. Let a few flowers remain for insects and for the simple pleasure of seeing orange, yellow, and red stitched through the green work of the vegetable bed. A nasturtium is not just a garnish. It is a border with flavor.
References
- North Carolina Extension Gardener Plant Toolbox: Tropaeolum majus
- Wisconsin Horticulture: Nasturtium, Tropaeolum species
- Royal Horticultural Society: Tropaeolum majus
- North Carolina Extension Gardener Plant Toolbox: Tropaeolum
- University of Minnesota Extension: Edible flowers
- Royal Horticultural Society: Three ways to use companion planting
