Growing an Allamanda for Vibrant Yellow Flowers

Yellow Allamanda is a tropical shrub or woody vine native to South America. It is also known as Golden Trumpet, Buttercup Flower and Brownbud. In Malaysia it is called Bunga Akar Kuning and in Thailand it’s common name is Baan Buree. Its scientific name is Allamanda cathartica L.(Vine) and Allamanda schottii (Shrub).

Where to Grow a Yellow Allamanda

Even though Yellow Allamanda is native to South America it is frequently seen in U.S. zones 9 and 10+ and in similar temperatures in Europe, like Spain, Portugal and such. It is best grown in a well drained soil; sandy soil is a bonus and it likes to be kept moist. However; it is extremely drought tolerant and even if it becomes a bit limp due to a prolonged shortage of water it will bounce back once it gets a good soaking.

For a spectacular show of flowers it requires a full sun position or at the very least a few hours morning sun. It seems unperturbed by dirt and grime and grows well on roadsides and highway medians. It is not salt tolerant so seaside gardens are not suitable for this Golden Trumpet. It does not tolerate frost.

Growing an Allamanda Shrub

The Allamanda shrub or bush, Allamanda schottii, is suitable for any size garden. It has evergreen, slim leaves and gives almost year round colour with 2.5″ wide yellow trumpet flowers. A stand alone bed of Allamanda schottii will constantly stay in bloom with selective pruning. The plant will remain in bloom but it is a vigorous grower so it can become a bit unruly and shoot off in different directions. In a mixed border this off-shooting can be very pleasing as it will bloom in between the stems and branches of other shrubs adding color and interest at will.

To keep the plants in check and to ensure twelve months of bloom do not prune all the plants at the same time, i.e. selective pruning. Pruning can be done at anytime once the bloom has died back, 3 or 4 times a year will not be a problem for this robust bush. The Allamanda schottii benefits from a severe pruning once a year – so by using selective pruning this will not appear unsightly or harsh.

The Allamanda bush will grow very well in containers and in this case the plant can grown in an area with a frost risk as the plant can be brought indoors for the cold months. Increasing the stock is easily done by taking 3″ cuttings, either softwood or hardwood, and potting them up.

Growing an Allamanda Vine

Growing an Allamanda vine, Allamanda cathartica L, is not something to be taken lightly. The vine is very vigorous and will require a strong support for its rapidly spreading branches. It does look spectacular in full bloom just tumbling over a pergola or garden wall. The blooms are 5″ wide and also trumpet shaped. The leaves are glossy and evergreen and much larger than the Allamanda bush.

Pruning an Allamanda Vine

Two Allamanda vines planted 15-20ft apart will have no problem covering a 30ft long trellis before their second year has ended. They are vigorous so pruning is a must. Pruning an Allamanda vine is not an easy task. There is always the temptation to just prune away the uppermost soft growth, leaving the more woody stems behind. This is a mistake as they will very quickly become one mass of dry dead weight. From the beginning it is imperative to keep the old wood cut away leaving room for the new shoots to flourish and bloom. After a severe pruning, feed the plants with an all-purpose fertilizer.

The Allamanda vine and bush are from the same family as the Oleander and the Plumeria and all three exude the same poisonous sap when cut. It may cause some irritation to sensitive skin. Caution is advised and gloves should be worn when handling these tropical golden beauties.