The Allamanda cathartica is the most widespread and cultivated species of the entire Allamanda family. Within the same species are found several varieties including the grandiflora, which has flowers of a light yellow up to twelve centimeters long, the Nobilis, with pale yellow flowers with a particularly intense scent and finally the williamsii, with small flowers striated with brown . This species is native to the Amazon area and is characterized by long leaves bright green, shiny and supported by very rigid woody branches. In the areas of origin the plant blooms and bears fruit throughout the year, while in temperate climates only in spring.
How to cultivate the Allamanda cathartica
This plant can be grown either in the external environment, such as along the perimeter of a wall or a trellis, as well as in pots. The only precaution to be taken is found in the fact that to thrive it requires a lot of light: it can in fact be exposed directly to the sun’s rays, taking care to avoid exposure during the hottest hours. The ideal range of temperatures to grow it is between 20 and 27 degrees Celsius, while in winter it can never fall below 15 degrees. In case this plant is cultivated in temperate climates whose winters know more rigid temperatures, it is advisable to raise the plant in pots in order to move it in a sheltered environment. To grow the plant as a climber it is advisable never to change the direction of the branches, but rather to favor their natural orientation. The plant should be watered regularly: it should always be remembered that it loves particularly humid environments, so it is also advisable to spray the leaves. The perfect soil consists of a mixture of three parts of garden soil, two parts of peat and a part of fine sand. This allows the soil to remain perfectly draining. The ideal vases are terracotta, on the bottom of which it is preferable to lay pieces of earthenware, which are able to ensure drainage. During the summer months a liquid fertilizer must be administered together with irrigation water.
Diseases and cures
One of the most frequent diseases of this plant manifests itself with white spots that appear on the leaves. Often the cause is the floury cochineal, which can be recognized as the virtues of the cotton flakes on the plant that, once manipulated, tend to fall easily. In case of small plants this problem can be eliminated by passing cotton soaked in alcohol, while if the plant is large it is preferable to use an insecticide. In the case in which the leaves seemed covered with small yellow spots, the cause would be to find the action of the red spider. Especially for infestations of a severe nature, it is appropriate to resort to the use of an acaricide product.
This species was discovered by Frederich Allamand, a Swiss botanist who lived in the eighteenth century. Another curious aspect concerns the lymph of the plant which, in contact with the skin, is stinging.