Allamanda, also known as Golden Trumpet and Yellow Bell, is a very popular flowering shrub suitable for open areas in a garden. It is fast growing, easy to grow and maintain, and adds colour to any landscape in no time, says N. CHANDRAMOHAN REDDY
They are few in species, but versatile in form. Grown as flowerbeds, ground covers, garden hedges, container plants, and climbing shrubs, the beautiful Allamandas are loved by all horticulturists.
With flowers resembling ‘trumpets’ and ‘bells’, they could create an acoustic imagery in garden!
Allamanda, also known as Golden Trumpet and Yellow Bell is a very popular flowering shrub suitable for open areas in a garden.
It is fast growing, easy to grow and maintain, and adds colour to any landscape in no time. With almost year-long production of flowers in striking hues, Allamanda is a favourite choice of many gardeners and landscapers throughout the warm regions of the world.
There are about 15 species of Allamanda , which are native to South and Central America. Out of these, Golden trumpet (Allamanda cathartica), Violet Allamanda (Allamanda blanchetii syn. A. violacea ), Bush Allamanda ( Allamanda schottii) and many cultivars of these three are popular in horticultural trade.
Allamanda is an evergreen, vigorous, perennial, woody compact shrub or creeping shrub.
The creeping varieties also climb a few meters on a support. Stems contain milky sap. Leathery, yellow-green to dark green leaves grow in whorls of two or four. They are lance-shaped or egg-shaped (ovoid).
Flowers are bright, trumpet-shaped, large, fragrant, and in yellow, white, cream, pink, or orange colours based on the species or cultivar. They are composed of five broad overlapping petals that spread outwardly. There are both single and double flower forms.
Clusters of flowers appear at the tip of new shoots or in the leaf axils. Allamanda blooms mainly during summer and monsoon.
With their varied forms, different species and cultivars of Allamanda can be used for various purposes, as flowerbed, for ground cover, as hedge, in containers, or as climbing shrub to be trained on low walls, and trellises. Since Allamanda is light-demanding plant, it may be planted only in open places where plenty of sunlight is available.
They grow well in slightly acidic soils with good drainage.
Since these plants require good amount of water during the growing period, they can bloom heavily even in the lawn areas, where enough moisture is available.
Stems are very flexible and are easy to weave through a trellis. Soft plant-ties can be used to hold each stem in place. Tie them loosely so that the growth is not restricted, and re-tie stems as they grow.
Regular and deep watering is needed for the plants, allowing the soil to dry slightly between waterings (but total dry soil will cause premature flower drop).
Continue watering as long as the plants are in blooms, but when flowering is finished during the early winter, keep them on the dry side until spring, allowing them to rest during the winter months.
Apply a balanced liquid fertilizer once in a month during the growing season and resume fertilization during April as the plant starts growing.
Because of their rapid growth, Allamanda plants require pruning frequently. Plants can be cut back to a third in the spring just before the growth resumes, to have more flowering. Prune back hard in the spring to improve the shape and encourage heavy flowering.
For the plants where Allamanda is used as hedge, continuous pruning is required to maintain the shape and compactness.
Though Allamanda plants are very hardy, insect pests like mealy-bugs, aphids, whiteflies, scales, and spider-mites may cause problems. The plants are susceptible to root-rot when overwatered during winter or planted under shade.
Watch for the symptoms of these pests and treat the infestation immediately with normal pest management practices.
Allamanda plants can easily be propagated by stem-tip cuttings during late spring. Clip four to five inches of semi-hard stem cuttings from fresh growth.
They should have at least three or four fully formed leaves at the tip. Make a diagonal cut at both the ends of the cuttings. Remove leaves and buds from the lower half and dip the cuttings in rooting powder.
Insert them in porous soil (either in a bed or in a container) and water enough to evenly moisten the surface of the soil.
Place them in a humid, warm, brightly lit area away from direct sunlight. The cuttings will root within two to four weeks, and be ready for transplanting.