Pot plants: Catharanthus, Madagascar periwinkle, Catharanthus roseus

Pot plants: Catharanthus, Madagascar periwinkle, Catharanthus roseus

Classification, origin and description

Common name: Periwinkle of Magagascar.
Kind: Catharanthus.

Family: Apocynaceae.

provenance: native to the whole tropical belt and not only to Madagascar.

Genre description: includes 7-8 species of annual and perennial plants, similar to periwinkles. The only species suitable for indoor cultivation is C. roseus.

Catharanthus roseus (photo website)

Species and varieties

Catharanthus roseus: native to the whole tropical belt and not only to Madagascar, this herbaceous species with bushy and erect habit, small in size, has opposite, oblong, shiny, dark green leaves with a white central grain. From April to October it produces flowers, 2.5 cm wide, formed by a small calyx and a corolla with a thin tube that opens into five divided and spatulated pink petals with a darker spot in the center of the orifice of the said tube. Although it is a perennial species, it is usually grown as an annual, since older specimens tend to become clumsy. It grows up to 30-40 cm. Among the different varieties we find: "Alba", with completely white flowers; "Little Bright Eye", with white flowers with dark pink central spot; "Little Pinkie", with completely pink flowers and a reduced size (25 cm).
Nb: it is poisonous to people and animals.

Catharanthus roseus varieta albus (photo website)

Environmental requirements, substrate, fertilizations and special precautions

Temperature: the minimum winter temperature tolerated is around 13-15 ° C.
Light: very strong. It also tolerates direct sun (especially in winter); but in summer a partially shaded position will allow for a more lasting flowering.
Watering and environmental humidity: watering must be frequent in summer; reduced in winter. The environmental humidity must be fairly high, especially in the winter months.
Substrate: a mixture of soil of manure, earth of leaves and sand.
Special fertilizations and tricks: in summer bring the plants outdoors in a position that allows them to be sheltered from the sun during the hottest hours. In autumn-winter bring the plants indoors and keep them in a very bright spot, even in front of a window.

Multiplication and pruning

Multiplication: they multiply by placing herbaceous cuttings (at the end of spring) or semi-woody cuttings (in summer) in a box filled with a mixture of potting soil and sand (in two to one ratio) maintained at a temperature of about 24 ° C.
Pruning: to obtain specimens with bushy habit it will be useful to prune the plants at 7-8 cm. from the base, in January-March. If they develop excessively, pruning can also be used in the summer.

Diseases, pests and adversities

- Leaves that wilt and flowers that do not last long: scarce watering.

- Aphids: attack leaves and flowers. They suck the sap and make the plant sticky. They are eliminated by washing the plant and treating it with specific insecticides.

- Cotton mealybug: can attack plants, especially in hot and dry climates. You have to remove them, treat the plant with an anticoccidic product and raise the humidity level (the spraying and the washing of the leaves allow to eliminate the cochineals in the larval state). As an alternative to the chemical, the affected parts can be rubbed with a cotton swab wet with water and alcohol.

Video: Madagascar periwinkle Catharanthus roseus