Catharanthus roseus: The madagascar perwinkle
From late spring and throughout the summer, gardens and terraces explode in a blaze of flowers and colors; among these, a place of honor belongs to the Madagascar Perwinkle which, with its abundant flowering, forms very pleasant flowering bushes and suggestive spots of color on windowsills and balconies.
The Madagascar perwinkle, whose scientific name is Catharanthus Roseus belongs to the Apocynaceae family and, as the name suggests, is native to Madascar where it grows wild. It is a perennial evergreen plant but it is considered annual because it fears a lot of cold and because, over time, it tends to lose its harmonic and compact shape.
However, it remains an excellent choice for beautifying terraces and balconies and for creating lively borders for flowerbeds and gardens. Its flowering is almost uninterrupted from April to October and does not require special care to grow luxuriant and flourishing. The flowering, which begins in late spring and ends at the first cold, is a succession of numerous small five-petaled flowers, white or pink with a pink-purple spot right in the center.
The bright green leaves are shiny and oval-shaped, striped with lighter veins. The whole creates a very special decorative effect. The only drawback is a poisonous plant for humans and animals, so it is good to place it in places inaccessible to children and pets.
Catharanthus roseus are simple plants to grow, also suitable for less experienced gardeners, they grow luxuriant in soft, fertile and draining soils. They prefer sunny and bright positions, but during the period of maximum heat it is advisable to protect them from direct sunlight. The ideal would be to expose them to the morning sun and protect them from the afternoon sun.
They are very afraid of the cold, so at temperatures below 13 degrees it is advisable to transfer them to the house where care is taken to place them in a very bright area, but far from direct sources of heat. The waterings must be frequent during the summer to allow the plant to maintain its right degree of humidity but always with the foresight to let the soil dry between one irrigation and another. In winter the need for water is very small.
For more abundant and vigorous blooms it is advisable to give, at least monthly, a good liquid fertilizer, rich in microelements that nourish the plant and stimulate its floral production.
Dangers and diseases
The Madagascar Periwinkles are plants resistant to pests and diseases, but they can run some risks, such as infestations of mealy cochineal, recognizable by the white spots on the underside of leaves. In this case you can intervene by “washing” the plant with water and marseille soap, and rinsing it perfectly.
Also, it can be attacked by plant lice, aphids or red spider mite. In all these cases you can use existing products on the market. If the leaves wither or curl and the flowers fall early it could be a lack of water or too high temperatures that do not allow the plant to maintain the right humidity.
In Madagascar and other tropical areas where the Catheranthus grows wild, it was used by local populations as a curative remedy for diabetes, especially for its “break-hunger” power.
In 1950 an important pharmaceutical industry, after extensive studies on the active ingredients of this plant, came to the discovery that the “vincristina” and the “vinblastina” contained in it, have therapeutic capabilities in the treatment of diseases of the lymphatic system such as leukemia and Hodgkin.
They developed the extraction and purification systems without attributing any recognition to the local populations that first discovered the therapeutic properties of the plant. This case is still re-evoked as emblematic of episodes of “biopiracy” that is the marketing of traditional medicines of a specific population.