Cantua is a plant you either love or hate. Sometimes people who grow it both love and hate it. Why? Well it produces some of the most attractive flowers you will ever see on a shrub but the plant itself has a somewhat scruffy appearance.
This plant - "The Sacred Flower of the Incas", or "Magic flower of the Incas" or "Sacred Flower of Peru" is a native of South America and renowned for the beauty of their large flowers. It grows in the wild of the Andes of Peru, Bolivia and Chile. About 12 species are known and they are classified as woody shrubs and trees and, in New Zealand, semi to almost evergreen.
The exotic drooping tubular shaped flowers long from terminal clusters of 6 - 12 flowers on the tips of long branches. 50 - 75mm long the flowers are long colourful tubes opening out like a trombone horn. They vary in colour from light yellow to bright red depending upon species.
They belong to the Polemoniaceae family which also includes a range of herbaceous annuals perennials and a few shrubs. A previous genus name for some species was Huthia.
The leaves are about 25mm long and are of a simple narrow shape. The branchlets are rather gnarled and spiky and look quite scruffy and even untidy.
Cantua tolerate a variety of conditions being drought resistant but survive in cooler moister areas as well. Good drainage is a key to success and they will tolerate cold areas once established. They tend to flower better in full sun with a little shelter.
They are generally easy to cultivate with the main activity being to prune off older stems to keep it young and vigorous. Propagation is by semi hardwood cuttings under normal conditions.
Species and cultivars
C. buxifolia (C. dependens). The most common and most popular species in NZ. Flowers are a brilliant red/pink or may range from purplish rose to cherry red depending upon the seedlings grown. It grows up to 1.5 metres high. Selected cultivars are offered in the USA.
C. bicolor. This is also available and it produces flowers which are tricoloured yellow, red and orange. It reaches about 1.5 metres high.
C. pyrifolia is a rare plant in NZ but produces curved yellow tubular flowers with white lobes.
C. tomentosa. Rare with salmon orange flowers.
C "Vanessa's Gold" A form selected in Nelson by Alan Jolliffe and marketed as "Vanessa's Gold". An excellent strong growing shrub well clothed in foliage and producing lemon yellow flowers several times a year. It grows up to 2 metres high.
Cantua sp. A creamy white form is reported in NZ.
Cantuas are not the prettiest plant in foliage and growth habit but produce these wonderful flowers. The make a great display when in flower. Cantua are best planted in the back of the border where their rather scruffy growth can be hidden by other plants but when in flower they need to be seen. They are excellent garden plants for a variety of situations and when in flower make a talking point.
It is covered with small ovate leaves and it produces bunches of pendulous, funnel-shaped flowers in spring and summer. It will survive in regions that receive little frost. In Christchurch try it in a sheltered place against the wall of a house or garage.
When not in flower the shrub often goes unnoticed. It should be pruned after flowering to encourage new growth and spectacular flowering.