Mahogany red, single to semi-double flowers.
A very ornamental and free-flowering species, it is often in bloom from early summer until cut down by the autumn frosts.
A climbing plant, it supports itself by twisting its leaf stalks around other plants etc. The flowers have a very pleasing mild scent.
A good companion plant in the garden, growing well with radishes, cabbages and fruit trees, improving their growth and flavour. A good companion for many plants, keeping many harmful insects at bay and also improving the growth and flavour of neighbouring crops. Aphids on nasturtiums indicate a lime deficiency in the soil.
Slugs and snails love eating this plant, so it can be grown to attract them away from other plants. The caterpillars of the cabbage white butterfly can be a nuisance and often cause considerable damage to the leaves.
Nasturtium has long been used in Andean herbal medicine as a disinfectant and wound-healing herb, and as an expectorant to relieve chest conditions. All parts of the plant appear to be antibiotic and an infusion of the leaves can be used to increase resistance to bacterial infections and to clear nasal and bronchial catarrh.
Tolerates most soils, though it prefers a rich light well-drained soil in full sun or partial shade. More and lusher leaves are produced when the plant is growing in a rich soil, though less flowers are produced. When grown in a soil of low fertility the leaves are smaller and less lush, though more flowers are produced. The plant will also succeed in very poor soils. It dislikes drought.
This species is not frost hardy in Britain but it is often grown in the flower garden as an annual when it will frequently self-sow. In cold springs, however, the seed will often not germinate until mid or even late summer, which is too late to produce a reasonable crop.
Sow April in situ. The seed usually germinates within 2 weeks. Seed can also be sown in March in pots in a greenhouse and planted out in late spring or early summer.
Leaves - raw. A hot watercress flavour. Very nice on its own or as a flavouring in mixed salads. Rich in vitamin C. The leaves are available from early summer until the first frosts of the autumn.
Flowers - raw. A very ornamental and tasty addition to the salad bowl, the flowers have a hot watercress flavour and are available all through the summer. The flowers contain about 130mg vitamin C per 100g.
Young seed pods - raw. These are even hotter than the flowers or leaves. They can also be harvested whilst immature and pickled for use as a caper substitute.
Seed - raw or cooked. Very hot. The mature seed can be ground into a powder and used as a pepper substitute. The seed contains 26% protein and 10% oil.