The nasturtium is a fast-growing, trailing or bushy garden annual with round shield-shaped leaves and bright, spurred flowers in orange, red and yellow, whose leaves, blooms and seeds are all edible and have a peppery taste. Native to the Andes of South America, the nasturtium has become a favourite cool-season flower in Indian gardens, pots and hanging baskets because it germinates easily and blooms even in modest soil.
The plant is also a useful teaching example of how a decorative flower can double as a food and a companion plant. This article explains what a nasturtium is, where it comes from, how to grow it in different parts of India, how its leaves and flowers are eaten, and what problems to expect.
Quick Facts
| Common names | Nasturtium, garden nasturtium, Indian cress (an old English name) |
|---|---|
| Scientific name | Tropaeolum majus (a smaller bush form is Tropaeolum minus) |
| Family | Tropaeolaceae, a small family in the mustard-oil order Brassicales |
| Origin | Andean region of South America, from Colombia southwards to Bolivia and Peru |
| Where grown in India | Home gardens, terraces and pots across the plains in the cool season; hill gardens through spring and summer |
| Flowering | Roughly six to ten weeks after sowing; plains from winter to early spring, hills from spring to autumn |
| Plant habit | Annual (perennial in frost-free climates), trailing or climbing to about two metres, or compact bush types |
| Uses | Ornamental flower, edible leaves and flowers, pickled seed pods, groundcover and trap crop for aphids |
Key Takeaways
- The nasturtium (Tropaeolum majus) is an annual garden flower from the Andes of South America that is widely grown in India during the cool season.
- Nasturtium is not related to watercress, though it shares the peppery flavour; both plants make mustard-oil compounds that give a sharp taste.
- The leaves of the nasturtium are round and peltate, which means the leaf stalk joins the blade near its centre, like the handle of an umbrella.
- Nasturtium leaves, flowers and young seed pods are edible, and the leaves and flowers are a good source of vitamin C.
- Nasturtium grows best in poor to average, well-drained soil with plenty of sun, because rich soil or heavy nitrogen feeding produces many leaves but few flowers.
- Gardeners often plant nasturtium as a trap crop, since aphids and cabbage white butterfly caterpillars are drawn to it and away from vegetables.
What is a nasturtium?
A nasturtium is a flowering plant of the genus Tropaeolum, and the garden form is Tropaeolum majus, an annual herb with soft, juicy, trailing stems, round leaves and funnel-shaped flowers. The flower has five petals and a long, slender spur at the back that holds nectar, and its colours range from cream and yellow to orange, scarlet and deep mahogany.
The family Tropaeolaceae is small and contains mainly this single genus. Many people are surprised that the plant is not a close cousin of the true watercress, whose botanical name is Nasturtium officinale. The common name was borrowed from watercress because the leaves taste similarly sharp. Botanists place Tropaeolum in the order Brassicales, which also includes cabbage, mustard and papaya, and many members of this order contain glucosinolates, the compounds responsible for hot, pungent flavours.
Two forms are most familiar in India. The trailing or climbing kind spreads over walls, fences and pots, while the dwarf or bush kind, often sold as compact seed mixtures, makes neat mounds suitable for borders and window boxes.
Where does the nasturtium come from?
The nasturtium comes from the Andean region of South America, where wild and cultivated Tropaeolum species grow in cool highland climates in countries such as Colombia, Ecuador, Peru and Bolivia. The garden Tropaeolum majus is believed to have arisen through natural hybridisation among South American species and was taken to Europe in the sixteenth century.
The scientific name has an interesting origin. The Swedish naturalist Carl Linnaeus, who named the genus in the eighteenth century, derived Tropaeolum from the Greek word tropaion, meaning a trophy. He thought of the shield-like leaves and the helmet-shaped flowers as the spoils of victory once hung on a post after battle.
From Europe the nasturtium spread across the world through colonial gardens and seed trade. It reached the Indian subcontinent through British-era gardens and hill stations, and it has remained a regular entry in seed catalogues for winter flower beds. Because it does not tolerate frost or very high heat, it fits the Indian cool season comfortably.
How do you grow nasturtium in India?
Nasturtium is grown in India by sowing its large seeds directly in sunny, well-drained soil or pots at the start of the cool season, and then watering moderately while the seedlings establish. The plant is forgiving and is often chosen by beginners because the seeds are large enough to handle easily and germinate within one to two weeks.
When to sow
- Plains of north and central India: sow from about October to December, so the plants flower in the mild winter.
- Peninsular and southern India: sowing is possible for much of the year in cooler districts, with the best results in the cooler, drier months.
- Hill regions: sow from March to June after the danger of frost passes, and the plants bloom through summer and early autumn.
Soil, light and water
Nasturtium prefers a sunny position with at least four to six hours of direct light, and a loose soil with moderate fertility. Soaking the seeds overnight and sowing them about two centimetres deep helps germination. The plant needs regular but moderate watering; waterlogged soil encourages rot, while prolonged drought stresses the plant and spoils the leaves.
Feeding
The common mistake is to feed nasturtium too well. Rich soil and extra nitrogen fertiliser create a large mass of lush leaves with few blossoms. Poor or only lightly composted soil encourages more flowers. A little leaf mould or compost at planting is usually enough.
Pots and baskets
Trailing types look excellent in hanging baskets, raised planters and terrace walls, where the stems can spill over the edge. In pots, use a mix of garden soil, sand and compost, and make sure the container has drainage holes.
Can you eat nasturtium leaves and flowers?
Yes, the leaves, flowers and immature seed pods of the nasturtium are all edible, and they have a peppery, slightly sweet taste that is often compared with mustard greens or radish. The flavour comes from glucosinolates that release a mustard-oil compound when the plant is chewed, which is also the reason the plant is sometimes called a natural source of pungency in salads.
Different parts are used in different ways:
- Leaves: torn into salads, sandwiches or chutneys, or blended into a pesto-style paste.
- Flowers: used fresh as a colourful garnish on salads, rice dishes and desserts, and sometimes stuffed.
- Green seed pods: pickled in vinegar and salt as a substitute for capers, an old kitchen tradition in Europe.
- Buds: pickled in the same way as the seed pods.
Anyone planning to eat nasturtiums should grow them without pesticides, wash them well and begin with small amounts, since the pungent taste can be strong and a few people are sensitive to it. Plants from a roadside, a nursery treated with chemicals or a bed sprayed with insecticides should not be eaten.
What are the nutritional and traditional uses of nasturtium?
Nasturtium leaves and flowers contain vitamin C and several plant pigments such as carotenoids and flavonoids, which is why the plant has a long reputation as a tonic salad herb. Historical European herbals describe it as a remedy for scurvy-like conditions because of its vitamin C content, though it is best seen as a flavourful garnish rather than a medicine.
Laboratory studies have found that nasturtium extracts contain compounds with antibacterial activity, and the mustard-oil derivative benzyl isothiocyanate has attracted research interest. These findings do not make the plant a treatment for infections, and anyone with a health condition should rely on medical advice rather than home remedies.
In the kitchen, a handful of fresh leaves can add a peppery bite where a gardener might otherwise use rocket or cress. The bright orange and red petals give colour to a dish without adding a strong taste of their own beyond a gentle sweetness at the spur.
How does the nasturtium help in a garden?
The nasturtium helps in a garden as a quick groundcover, a pollinator plant and a trap crop that draws pests away from more valuable vegetables. Its sprawling stems cover bare soil within weeks, shading the ground and reducing weeds, while the open, nectar-rich flowers are visited by bees, hoverflies and butterflies.
As a trap crop, nasturtium attracts black aphids and the caterpillars of cabbage white butterflies, which prefer its leaves to those of cabbage or cauliflower in some situations. Gardeners sometimes plant a few nasturtiums around the vegetable bed and remove infested leaves, rather than spraying the whole plot. This approach works best when the nasturtiums are monitored, because heavily infested plants can become a source of pests.
The plant is also used as companion planting around fruit trees, near beans and squash, and along the edges of raised beds. Its tendency to scramble means it is easy to train on a low trellis, over a rock garden or along a fence line.
Which pests and problems affect nasturtium?
The main problems of nasturtium are aphids, caterpillars of the cabbage white butterfly, whiteflies and, in humid weather, fungal leaf spots and root rot. Most of these are manageable by hand picking, washing leaves with a jet of water and ensuring good drainage and air movement.
| Problem | Typical sign | Simple response |
|---|---|---|
| Aphids | Clusters of tiny black or green insects on stems and under leaves | Wash off with water, pinch infested tips, encourage ladybirds |
| Cabbage white caterpillars | Ragged, eaten leaves and green larvae | Hand-pick caterpillars regularly |
| Whiteflies | Tiny white insects fluttering when disturbed | Use sticky traps and keep plants airy |
| Leaf spot or mildew | Brown patches or white powder on leaves | Avoid overhead watering, remove affected leaves |
| Too few flowers | Dense foliage but little blooming | Move to full sun and cut back nitrogen feed |
Because nasturtium is often eaten, gardeners are advised to avoid strong chemical pesticides altogether and to depend on mechanical and biological control methods.
How is nasturtium propagated and does it spread?
Nasturtium is propagated almost entirely by seed, and it spreads by self-seeding wherever flowers are left to mature. Each flower produces a three-lobed fruit that splits into three large, wrinkled seeds, and these drop to the ground or can be collected for the next season.
Collecting seeds is simple. Gardeners let a few pods turn pale and dry on the plant, then store the seeds in a paper packet in a cool, dry place. The seeds keep well for a year or more. Named double or variegated varieties are sometimes propagated by cuttings, but those methods are uncommon in India.
In cool hill gardens nasturtium can self-seed in successive years and appear in unexpected places. In the plains it usually dies back with the arrival of hot weather and returns only if the seeds survive. It is not considered a serious invasive plant in India.
What varieties of nasturtium are available?
Nasturtium varieties are grouped mainly into trailing, climbing and dwarf bush types, with a choice of single or double flowers and plain or variegated leaves. Seed packets sold in India usually carry mixed colours, and named strains are marketed under names that highlight shades such as scarlet, gold, mahogany or salmon.
- Trailing and climbing types: long stems that suit baskets, fences and slopes.
- Dwarf or bush types: compact plants that are good for borders and small pots.
- Variegated types: leaves marbled with cream or pale green, striking even without flowers.
- Double-flowered types: blooms with extra petals that look fuller but set seed less freely.
Is nasturtium related to any other food plants?
Nasturtium is related to a few other Tropaeolum species, the best known being the Andean tuber crop mashua, Tropaeolum tuberosum, which is grown for its edible roots in high-altitude South America. Mashua is rarely seen in India, but it shows that the genus has long been valued for both food and decoration.
Outside the genus, the nasturtium shares its pungent chemistry with mustard, radish, cabbage and horseradish, all of which belong to the order Brassicales. This helps explain why the taste of a nasturtium leaf feels familiar to anyone who has eaten radish leaves or mustard greens, even though the plants are not closely related in structure.
Bottom Line
The nasturtium is an easy, cheerful cool-season flower that also supplies peppery leaves and blooms for the kitchen. It does best in sun, lean soil and moderate watering, and it rewards even beginners with weeks of colour.
Frequently Asked Questions
What is a nasturtium?
A nasturtium is a trailing or bushy annual garden plant, Tropaeolum majus, with round leaves and bright orange, red or yellow spurred flowers. It comes from the Andes of South America. Its leaves and flowers are edible and taste peppery.
Is nasturtium edible?
Yes, nasturtium leaves, flowers and young seed pods are edible and have a peppery flavour. They can be added to salads or used as a garnish, and the green seed pods can be pickled like capers. The plants should be grown without pesticides and washed before eating.
When should I sow nasturtium seeds in India?
In the plains of India, nasturtium seeds are best sown from October to December, while in hill regions they are sown from spring to early summer after frost has passed. The large seeds germinate in one to two weeks when planted about two centimetres deep in sunny, well-drained soil.
Why is my nasturtium all leaves and no flowers?
A nasturtium produces mostly leaves when the soil is too rich or too heavily fed with nitrogen fertiliser. Flowering improves in poorer soil with full sun, moderate watering and little or no extra feeding. Shade can also reduce blooming.
Is nasturtium the same as watercress?
No, nasturtium is not the same as watercress, although the two share a peppery taste. Garden nasturtium belongs to the genus Tropaeolum in the family Tropaeolaceae, while true watercress is Nasturtium officinale in the cabbage family Brassicaceae.
Do nasturtiums attract pests?
Yes, nasturtiums attract aphids and cabbage white butterfly caterpillars, which is why gardeners use them as trap crops. Placing a few plants near vegetables can draw pests away from the main crop, but infested nasturtium leaves should be checked and removed regularly.
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