A fast-growing, climbing tender perennial, that can be grown successfully as a half-hardy annual in the UK. Quickly climbs by means of tendrils arising from the leaf stalks. Useful for providing temporary vertical cover or interest.
Family: Polemoniaceae (Polemonium family)
Botanical Name: Cobaea
Common Names: Cup-and-saucer vine, Cathedral bells, Mexican Ivy
Foliage: Evergreen leaves with three pairs of leaflets.
Flowers: Bell-shaped flowers with prominent stamens. In shades of either green and violet or greenish white, which turns violet-purple.
Flowering Period: May to October.
Soil: Well-drained, moderately fertile soil (chalk, sand or loam). Any pH.
Conditions: Best in full sun. Grow in a west or south facing aspect, in a sheltered position.
Habit: Self clinging climber.
Type: Tender perennial (grown as half-hardy annual).
Origin: Central and South America.
Hardiness: Half-hardy (tender) in the UK. Protect from frost and cold weather.
Grow in a sunny sheltered spot, supported by a warm wall, archway, obelisk or trellis. Climbs using tendrils.
Plant in a well-drained soil that is not too rich. Avoid heavy clay soils. Harden-off fully before planting out.
The flower display can be disappointing in poor summers.
Water regularly during dry weather. Avoid waterlogged conditions.
To improve flowering, apply an all purpose flowering plant food (slightly higher in phosphorus and potassium) every few weeks, or use a slow release form. Do not over fertilize.
Deadhead regularly to extend the flowering period.
Can be affected by Aphids. Generally disease free.
Sow seeds in March under glass in a gentle heat (around 18°C). Soak seeds for a few hours before sowing. Pot on, harden off and plant out once all danger of frost has passed in your area.
Cobaea scandens (Mexican cup-and-saucer vine) is the main species. A quick-growing climber with fragrant purple flowers. Supported height to 10ft (3m). Variety 'Alba' has off-white (yellowish green) flowers. For sale at Crocus.