Climbing nasturtium
A whole palette of colours
Today’s growers can choose from many colours of nasturtium. The classically beautiful reds and oranges have been joined by everything from cream-coloured to black-red varieties. They all go well together.
Originally nasturtium was grown as a crop in the Andes mountain range of South America. As nasturtium is a valuable source of vitamin C, it was used by sailors to prevent scurvy. But you don’t have to be at sea to enjoy the vitamins and summer colours of nasturtium.
Sowing nasturtium
Nasturtium can be sown directly or pre-grown. We usually pre-plant a few individual plants to enjoy a really early flowering. Then we direct sow the rest of the seeds outdoors or in pots.
- Direct-sow nasturtium outdoors
Nasturtium is a fast-growing flower. It is therefore great to direct sow outdoors in May-June. The soil temperature should have reached at least 15 degrees. Soak the seeds for 24 hours before sowing to speed up germination. Place the seeds about 2 cm deep and keep them moist during germination.
- Propagate nasturtium indoors
If you want really early flowering, you can propagate nasturtium indoors. Soak the seeds for 24 hours before sowing, so they germinate faster. Place the seeds about 2 cm deep and keep them moist during germination. Creeping nasturtium is a vigorous plant that emerges early and grows quickly. Therefore, calculate sowing to 2-3 weeks before planting out.
Bulbous plant, ground cover or trellis creeper?
Climbing nasturtium thrives best in the sun, but can also be planted in partial shade. Keep a planting distance of about 10-20 cm. Depending on the variety, cress can grow to 1-4 metres.
Climbing nasturtium looks great on a trellis, a fence or a pergola. It also looks great as a ground cover. Because slinger cress grows quickly, it is very good as a border plant or to fill in gaps in the border. It also looks great in a hanging basket or balcony box.
Because nasturtium is an edible and beautifully flowering plant, it also has a place in the vegetable garden. Even there, cress can grow at a height. Perhaps it can be planted alongside broad beans or tied-up cucumber plants? Or it can climb on the ground and scatter its flowers between rows of leafy greens and root crops.
Caring for nasturtium
Nasturtium is a grateful and undemanding plant. It should not be overfed, as this will result in more foliage than flowers.
What nasturtium can suffer from is aphids. To prevent and discourage infestations, shower the leaves with a soft spray. If aphids get a foothold, a soap spray can work wonders. Mix 0.5-1 dl of green soap in a litre of water and spray daily until the aphids are gone.
Remove wilted flowers to stimulate new ones to form. But feel free to let some flowers go to seed to use them in cooking.
Spicy capers from nasturtium seeds
Harvest nasturtium all season long. The plants are very sensitive to frost, so be sure to pick off the leaves, flowers and seeds when the frost nights are approaching.
The whole plant is edible and has a mildly peppery flavour. The leaves are good as a seasoning in salads. The flowers and leaves are great in green salads and potato salads and as a decoration on pies, soups, cheese trays and sandwich cakes. The large nasturtium flowers give food a summery splash of colour.
The seeds of nasturtium are popular for pickling to use much like capers. You boil the green seeds for 1-3 minutes, put them in a jar and pour over boiling apple cider vinegar or pickle juice.
Author: Johanna Damm
Fact-checked by Erik Hoekstra
Last updated 2022-10-14