Height 23cm-3.6m (9in12ft)
Planting distance 38cm (15in)
Flowers early summer to early autumn
The spurred, lightly perfumed orange and yellow, trailing stems and round, smooth, green leaves of this hardy annual are one of the most familiar summer sights in gardens. The blooms appear from early summer until early autumn and grow on compact, trailing or according to variety.
Nasturtiums can be grown in containers and hanging baskets, in bedding schemes or the fronts of borders, and they can be trained up a wall or trellis. However, blackflies find the smooth green leaves irresistible, and will destroy the plants if they are not controlled.
Most garden varieties have been developed from Tropaeolum majus and include the following.
These have a compact bushy habit and reach 23cm (9in) high.
‘Alaska Mixed’ has single red and orange flowers. The pale green leaves are marbled with cream.
‘Empress of India’ has deep crimson-scarlet flowers and dark green leaves.
‘Tom Thumb Mixed’ has single flowers in shades of red, orange and yellow.
‘Whirlybird Mixed’ has a mass of semi-double blooms in mixed colours. These are held well above the foliage and face upwards. Single colours – scarlet, mahogany, cherry, tangerine, orange, gold and cream – are also available.
SEMI-TRAILING VARIETIES These have a trailing habit and reach 30-38cm (12-15in) high.
‘Double Gleam Mixed’ has fragrant double and semi-double flowers in golden-yellow, orange and scarlet.
‘Jewel Mixed’ is an early-flowering mixture with semi-double blooms in mixed colours.
CLIMBING VARIETIES reach 1.8m (6ft) or more high and are suitable for training up trellis and walls.
‘Climbing Mixed’ is a free-flowering variety with single flowers in crimson, orange, yellow, cream and bicolours.
Tropaeolum peregrinum is a short-lived perennial species usually grown as an annual. Rapidly reaching 3.6m (12ft) high in one season, it bears irregularly shaped yellow flowers with green spurs from mid summer to mid autumn among blue-green leaves. It will tolerate shade.
Sow the seeds 2cm (3/4in) deep in poor soil in a sunny site. Thin to 38cm (15in) apart. With Tropaeolum peregrinum sow two seeds where one plant is required and if both germinate remove one. This species requires ordinary garden soil.
To cultivate plants for hanging baskets, sow the seeds in late winter to early spring in pots or pans of seed compost at a temperature of 13-16°C (55-61°F). When the seedlings are large enough to handle, pot them singly in 7.5cm (3in) pots of compost and pot on as required. Harden off and plant out in early summer.
Pests and diseases
Blackfly may infest leaves and stems and virus diseases may affect leaves.