The Allamanda is one of the group of semi-climbing, upright growing plants, becoming more and more popular nowadays. The most popular being Allamanda cathartica plant. They can also become an evergreen shrub-like plant with pruning.
This woody vine grows vigorously in full sun or semi shade, even in poor soil.
The plant climbs grows rapidly, making it good vine for use over pergolas or on structures with some horizontal support.
The variety Allamanda cathartica var. hendersonii has larger flowers with wider petals.
Growing The Allamanda Plant
Allamanda cathartica is a strong vine plant/climber, large yellow blooms with shiny deep green, leathery, 2-4 inch evergreen leaves, with large clear yellow bell-like flowers.
Flowers and Fragrance
The bell-shaped allamanda flower is very fragrant, yellow and appearing in summer can reach 4-5 inches across. Flowers can last until late November and into December in the South.
Allamanda Bush Care
Overall, the Allamanda vine perfectly combines the beauty of their whorled leaves, trumpet-shaped flowers, and twining growth, to make them garden favorites.
Light and Temperature
In its native habitat, new shoots find their way to the tree tops to get all the sun they can, while keeping the dark green leaves protected in semi-shade.
A lover of sun, this drought-tolerant plant needs lots of sunshine, so if possible, mimic nature and shade the plant but give the tips lots of sunshine.
Keep temperatures and humidity high if possible.
Watering Your Allamanda & Fertilizing
When in full growth season, in high temperatures and humidity Allamanda requires lots of water. During its flowering period pay attention to the plant’s water use. Very often it requires some extra water to avoid flower loss.
Fertilizing Allamanda cathartica is best with a liquid water-soluble plant food once every two weeks during active growth. Do not give too much fertilizer to avoid overcrowding of foliage and lesser flowers.
Soil and Planting
As with many vines Allamandas like good, rich soil. If grown in a container transplant every two years. If the plant is large, do not step up to a bigger gallon pot, but prune the roots instead and replace with a rich potting mix.
Providing support with a trellis will allow the plant to “show off” to its fullest. The photo at the right is of Allamanda ‘Golden Trumpet vine’, one popular variety of Allamanda plants.
Allamandas are popularly used as ornamental plants. They can be grown in sheltered areas as well as indoors – with care – as potted plants.
In the tropics, Allamandas are often pruned and used as blooming hedge plants. This tropical plant’s growth can be controlled so that they become slender trees crowned with their glorious blooms at the top portion of the plant.
Allamanda Bush – Spectacular in Greenhouses or Sun Rooms
These tender tropical evergreen climbers make a breath-taking spectacle in Northern greenhouses or sun rooms. Glossy green leaves are mostly large, accompanied by trumpet-shaped flowers come in several colors, always brilliant. Even the red-brown buds are appealing.
The allamandas’ long, trainable stems admit them to classification as vining plants. But the growth is lax and pliable only when it is young, and becomes brittle at maturity.
On established plants, train some young shoots gently down to cover what might be a bare base. Any support (like a trellis) should be sturdy and lasting.
Pruning and Allamanda Flowers
Allamandas under ideal conditions, can grow rapidly and get out of control, making pruning essential. Allamanda plants can become shrubs with pruning.
It’s important to remember when pruning Allamandas that the blooms appear in clusters at the tip of new shoots. Pruning or cutting back new shoots will affect the blooming of the plant. Prune carefully and selectively.
Spring is the best time prune before the growing season begins. Unless you plan on training the vines on a trellis, the long vines or shoots can be pruned back.
Older more mature plants should not be cut back too hard.
Allamanda In The Southern Garden
In Southern gardens the allamandas are used in many ways – as accent or specimen in landscape or border; trained or espaliered against fence or wall; on all kinds of garden structures; and even as a showy hedge.
In any climate, they are brilliant subjects for a showy display in outdoor containers, if they can be brought indoors for the winter.
The plants need a full ration of sun, fertilizer, humidity, and moist, well-drained soil during the growing season, and temperatures not less than 55° degrees Fahrenheit.
In the spring, when new growth begins, mature plants are repotted and cut back to ripe or half-ripe wood. When summer flowering has finished, hold back water almost to the point of wilting the leaves; let the plant rest, and keep the soil fairly dry until early the following year.
Propagate by stem-cuttings of half-ripened wood in spring. For safety’s sake, insert at least two joints in the propagating medium, over bottom heat or in something like a soda bottle planter.
Allamanda Pests and Problems
Wilting Leaves and Dropping Shoots – This is a sign of lack of water. Make sure the plant is receiving enough water, especially during warm, dry times of the year.
If the plant is potted and “drys out”, set the pot in a bucket of water to allow the soil to “soak up” the media thoroughly.
Plumeria Caterpillars – Pseudosphinx tetrio species, with common names frangipani hornworm, rasta caterpillar, feeds and pupates on the leaves of Apocynaceae plants including those of Allamanda shrubs. As they reproduce fast, an infestation can quickly result to defoliation.
Apart from infesting oleander shrubs, some gardeners experience oleander caterpillars infestation in their Allamanda plants.
Spider Mites – More common when growing Allamanda on a sun porch or greenhouse. Pale looking foliage and cobwebs on the underside of leaves. Leaves begin to drop. Try treating with a miticide.
Brownish Spots / Stunted Growth – Look for aphids on tender growth. Use a natural insecticide, neem oil for plants or other controls for aphids.
When buying Allamandas look for plants plants with fresh growth and shiny leaves. Check for pest such as aphids on new growth and spider mites on undersides of leaves.
Difficulty: Not the easiest plant to grow indoors – but happy in areas with lots of bright light like sunrooms or greenhouse where more ideal conditions exist.
Allamanda cathartica hendersoni – Golden funnel-flowers up to five inches across.
Allamanda cathartica williamsi – Similar yellow flowers with red-brown throats.
Allamanda neriifolia – oleander allamanda – Shrubby or half-clinging to about three feet, with large golden flowers.
Allamanda blanchetti – also known as purple Allamanda. A native to Brazil cultivated as an ornamental plant.
Allamanda violacea – Slender climber with reddish-purple flowers, usually grafted onto cathartica stock.