When people talk about “nasturtium”, most mean the edible nasturtium (bot. Tropaeolum majus), although there are a few other very interesting species for balconies and gardens.
However, the Tropaeolum majus, which is easy to cultivate, is the most widespread variety of the genus in gardens and on balconies, which is why this article provides you with detailed instructions for planting and care – and of course, at the end, you will find a list of the most beautiful species and varieties.
origins of nasturtium
The nasturtium (bot. Tropaeolum majus) comes from Central and South America, where it mainly grows wild in Brazil and Peru, but also in Chile and Bolivia. It is probably the best-known representative of the nasturtium plant family (bot. Tropaeolaceae), which has around 90 species, and the garden form used in this country is a hybrid.
The wild form is considered a medicinal plant in its homeland because of its antibacterial ingredients, which is why it was named “medicinal plant of the year” in 2013.
The nasturtium is a climbing plant that, thanks to its long and densely leafy tendrils, is ideal as a privacy screen and for greening pergolas and garden fences. The plant grows reliably and quickly on any climbing aid – both in height and in width.
Plant the species directly in the bed or in a flower box or pots, whereby the different colored varieties can be used to create pretty arrangements on the balcony or in the flower bed.
A planting in a raised bed placed on the terrace, in which you have installed a trellis, looks particularly pretty – this way your favorite spot in the garden gets a green privacy screen.
Planted without climbing aids, the large nasturtium also cuts a fine figure in hanging baskets – with drooping shoots – or as ground cover. But be careful: the plants take every opportunity to climb!
You can also plant the medicinal and kitchen plants in the vegetable patch to ward off pests and diseases, especially in plantings with longer-growing crops such as broccoli, cauliflower, kohlrabi, celery, radish, beans, peas, cucumbers, or fennel. In addition, planting apple and peach trees and rose beds counteracts lice infestation.
Used as a culinary herb and medicinal plant
The natives of South America have been using nasturtium as a remedy for many centuries. The infusion is said to help with colds, bronchitis, and infections of the urinary tract in particular, but excessive consumption quickly has an irritating effect on the gastrointestinal tract due to the pungent substances it contains.
For this reason, you should only use the hot and spicy tasting leaves and flowers of the plant sparingly in the kitchen, for example in salads, sauces, or herb butter. The nasturtium also tastes great as a topping for bread.
On the other hand, you can soak flower buds that are still closed and unripe fruits in herbal vinegar and use them as a tasty substitute for capers. Furthermore, a decoction of fresh leaves and flowers can be used for hair care, for example as a conditioner for fragrant hair.
appearance and growth
In its native South America, the nasturtium grows perennial. With us, on the other hand, the plant does not survive the cold and wet winters, which is why it dies with the arrival of the first frost.
However, their seeds usually survive the cold season without any problems, so new plants will germinate in the same place next spring. The large nasturtium grows creeping and forms long tendrils that can reach lengths of three to five meters.
Therefore, the species is very suitable as a ground cover but strives upwards at every opportunity. The plant forms round, thin stems on which the leaves and flowers stand upright at a height of about 20 centimetres (7.8 inches).
The large, shield-shaped leaves of the large nasturtium have a smooth edge and are light to dark green in color, depending on the variety. The nine clearly recognizable leaf veins, which radiate out from the center, are also characteristic.
Also typical of the species is the so-called lotus effect, in which water that hits the leaves simply rolls off. The hot and spicy-tasting leaves can be used fresh or raw as a herb and taste finely chopped in herb butter, quark, or salad, for example. Young and light-colored leaves have a significantly milder taste than older and darker leaves.
flowers and flowering time
The nasturtium owes its name to the capuchin monks, whose robes with the pointed hoods remotely resemble the large, showy flowers with the pronounced spur. The calyxes are usually bright red, orange, or yellow in color and can also be monochromatic or patterned.
They appear between July and October and appear decoratively as single flowers on the long tendrils. The flowers also have a pungent aroma reminiscent of the taste of mustard but are somewhat milder than the leaves.
They are very suitable for decorating salads or desserts, but be careful: catchy tunes like to hide inside, which you certainly do not want to eat with them. Gently shake the flowers after picking, then the little animals will fall out. Pollination is by insects,
The nasturtium fruit
After flowering, the large nasturtium forms one-seeded split fruits, which are quite large and which are also edible as capers when unripe. When mature, you can dry and grind them – they make a slightly hot seasoning powder for soups, sauces, and stews.
Be careful when cultivating outdoors in the garden: nasturtium likes to sow itself – although the plant itself is not hardy – so that you can be surprised with numerous seedlings next spring.
is nasturtium toxic?
The large nasturtium is not poisonous, but can instead even be used as a spice and medicinal herb. However, this is not true for all species of the genus, which again may not necessarily be poisonous but are still not edible.
Traditionally only Tropaeolum majus and Tropaeolum tuberosum are used as food plants.
suitable location for nasturtium?
The nasturtium is one of the sun-loving summer bloomers and thrives best in a sheltered, sunny location in the bed or on the balcony. The exposure to light has a direct influence on the luminosity of its flower colors and on the number of flowers: the sunnier it is, the more flowers it forms – in addition, these get all the stronger colors, while specimens cultivated in partial shade and shade mainly have leaves and only a few, develop pale lasting flowers.
Suitable soil for nasturtium
The nasturtium also develops many leaves but only a few flowers in nutrient-rich soil. Therefore, place them in soil that is only moderately humus-rich, if possible with a higher proportion of clay and/or sand. This should be well-drained, as the plant-like so many – does not tolerate waterlogging.
As a substrate for pot culture, use a humus-based potting or potting soil that you can thin with a little sand.
sowing the nasturtium
In the flower bed, the nasturtium, which is only one year old in our country, usually sows itself. In addition, you can prefer the plants between February and April on the windowsill, which works best as follows:
- Soak seeds in warm water for a few hours
- Fill the growing pots with the nutrient-poor substrate
- Dig pea-sized seeds two to three centimeters deep
- keep in a bright but not directly sunny place at room temperature
- Keep substrate evenly moist
- tense air (covering with foil or similar) promotes germination
- Germination occurs after two to three weeks
- Planting out in the bed is possible from the end of May after the last late frosts
Early nasturtium flowers faster, but you can also sow the seeds directly into the bed or planter from May. The plants grow very quickly so it is not absolutely necessary to prefer them. Sowing is possible until the end of June.
Watering the nasturtium
The water requirement of the nasturtium depends very specifically on its location: the sunnier and warmer the plant is, the more water it needs – especially since the species evaporates a lot of moisture due to the large leaf mass and therefore has a high water requirement from the outset.
Potted plants should therefore be watered daily in the summer months, provided it is dry and not raining. If there is a lack of water, the plant will immediately drop its leaves. Also, always water from below and never over the flowers, as they will then fall off.
Fertilize the nasturtium properly
Fertilization should also be avoided for potted plants since an excess of nutrients only stimulates leaf growth – at the expense of the abundance of flowers.
Cutting the nasturtium properly
You can cut off tendrils that are too long and faded shoots with sharp, clean scissors. In particular, removing the flowers extends the flowering period so that you can enjoy the bright colors well into autumn. To obtain seeds, simply leave a few flowers on the plant and harvest the ripe fruit in the fall.
In early autumn you can take cuttings that root very quickly. However, you must overwinter them and only plant them out in the following spring.
hibernating the nasturtium
Although a frost-free but cool overwintering (e.g. in an unheated winter garden) of the non-hardy nasturtium is basically possible, this makes little sense due to the uncomplicated cultivation of the plant.
Care during the winter months is more complex than annual re-sowing, especially since pests and diseases like to nest during the winter.
Diseases and pests that affect nasturtium
With its mustard oils, the nasturtium is very successful in defending itself against many fungi and pests, which is why you can plant it in flower and vegetable beds as a preventive measure.
Nevertheless, the plant is popular with aphids (and they keep the insects away from the roses, for example) and the cabbage white, which likes to lay its eggs on the leaves. A caterpillar infestation is indicated by the typical feeding marks.
Yellow leaves, if they occur only sporadically, are normal and are simply plucked off. If, on the other hand, the discoloration occurs more frequently, this is often an indication of too much or too little water.
Nasturtium species and varieties
There are around 90 different species of the genus Nasturtium, with only five species being cultivated as ornamental plants. The various varieties of the small nasturtium (bot. Tropaeolum minor) are particularly suitable for cultivation in balcony boxes and pots, as they only grow to a height of about 30 centimeters (11 inches) and have a rather bushy growth.
Tropaeolum majus, the nasturtium, on the other hand, is the well-known edible species. However, this develops tendrils up to three meters long and should therefore be given a place in the garden.
We will present other species and their varieties in more detail here.
Large nasturtium (bot. Tropaeolum majus)
The fast-growing species is native to the forests of Brazil and Peru, but has also been cultivated here for a long time. The great nasturtium grows bushy or creeping, depending on how it is grown. Without a climbing aid, the plant only grows to a height of around 50 centimetres (20 inches), with climbing options – such as a wall or a fence – it can reach a height of up to three meters (10 feets) in good growth conditions.
The different varieties usually flower yellow, orange or red. But there are also two to multicolored varieties, whereby the color of the flowers is usually dependent on the weather: the colors remain pale in cool temperatures and little sun.
They only get their luminosity in warm summer temperatures and lots of sunlight. Both the leaves and the flowers of the species are edible, you can also pickle the buds and the unripe fruits as fake capers. The species is an annual and dies at the end of summer, but its seeds overwinter and germinate on their own in the following spring.
Examples of popular varieties are:
- ‘Alaska Mix’: multicolored flowers, white variegated leaves
- ‘Bunte Juwelen’: multicolored mix with ruffled flowers
- ‘Cherry Rose’: cherry red flowers
- ‘Cream Troika’: light yellow flowers with dark spots
- ‘Jewel of Africa’: Mixture of different colored flowers
- ‘Salmon’: salmon-colored flowers
- ‘Milkmaid’: light yellow flowers
- ‘Moonlight’: light yellow flowers
- ‘Night and Day’: flowers in two colors, white and dark red
- ‘Orange Troika’: bright orange flowers
- ‘Orchid Flame’: yellow-red patterned flowers reminiscent of orchids
- ‘Scarlet Glory’: semi-double, bright red flowers
- ‘Variegated Queen’: Variegated mix with mottled foliage
The subspecies Tropaeolum majus ‘Nanum’ remains low at around 30 centimeters (20 inches) and does not climb. It is very suitable for pots and other planters on the balcony or terrace.
Kleine Kapuzinerkresse (bot. Tropaeolum minor)
The small nasturtium, native to Peru and Ecuador, grows rather bushy and is between 30 and 59 centimeters high (20-23 inches). Your shoots do not twine. The flowers, which mostly bloom in yellow and red tones, appear between June and September and adorn sunny to light, partially shaded locations on the balcony or terrace. Plants will not grow in the shade.
Examples of popular varieties are:
- ‘Black Velvet’: dark purple flowers with a yellow centre
- ‘Gartenjuwel’: different colored mixture with bright colors
- ‘Empress Viktoria’: velvet red flowers
- ‘Oriental Magic’: deep velvet red flowers
- ‘Peach Melba’: peach-colored flowers with a darker centre
- ‘Sangria’: beautiful, bright red flowers
- ‘Sun Carpet’: bright yellow flowers
- ‘Tip Top Scarlet’: numerous fiery red flowers
- ‘Vesuvius’: salmon-colored flowers
- ‘Whirlybird’: variegated mix of red and yellow semi-double flowers
Canary Capuchin Cress (bot. Tropaeolum peregrinum)
This species, also known as “canary nasturtium”, comes from Central America and has a good reason for its name: the yellow flowers are characterized by strikingly large petals with slits on the edges and therefore look like bird wings. The species, which is perennial in its homeland, is not hardy and is therefore only cultivated here as an annual.
The climbing tendrils are up to two meters high and require a trellis or other climbing aid. The fast-growing climbing plant is suitable for greening pergolas and wire mesh, but can also be grown in hanging baskets, hanging baskets or in pots. A popular variety is the ‘Goldranke’ with its bright golden yellow flowers.
Knollige Kapuzinerkresse (bot. Tropaeolum tuberosum)
The species, also known as “Mashua”, grows primarily in Peru and Bolivia and serves the local population as a source of food, as the tubers of the plant are edible – cooked or roasted.
Here, the bulbous nasturtium is rarely grown but can be cultivated in a similar way to dahlias: dig up the bulbs before the first frost and store them in a dark and cool place to replant them next spring. The species is a climbing plant whose fast-growing tendrils reach up to four meters high and require climbing aids.
Dreifarbige Kapuzinerkresse (bot. Tropaeolum tricolor)
Tropaeolum tricolor, the tricolor nasturtium or Chilean nasturtium, is a perennial plant species from the Tropaeolaceae family. The species is endemic to Chile, where it grows in the cloud forest of the coastal mountains of northern Chile at an altitude of 300 to 900 meters (900- 2500 feet) and further south in the temperate forests of the interior.
The tubers are hardy down to about minus eight degrees Celsius (17 F) and can also tolerate a snow cover for a short time. The most striking feature of the climbing plant are its numerous – as the name suggests – three-colored flowers in red, yellow, and blue.