Classification, origin and description
Common name: Heliotropes, Vainiglia.
provenance: warmer regions of the globe.
Genre description: includes about 250 species of herbaceous or shrubby plants. They are the latter to be grown as pot plants or to form flower beds. They are quite delicate and need protection during the winter season. They produce variously colored and highly fragrant flowers, which appear in the summer.
Heliotropium arborescens (Berlin Botanical Garden) (photo website)
Species and varieties
Heliotropium arborescens: is the classic heliotrope with dark purple flowers.
Heliotropium peruvianum: also called "flower of the ladies", this species has oblong leaves with maracate ribs. In summer it produces very fragrant violet flowers. It can reach a height of 2 m.
Heliotropium x hybridum: species of horticultural origin, obtained by crossing H. corymbosum with H. peruvianum, has oblong leaves, with a wrinkled and dark green leaf. In spring and autumn (but flowering can take place throughout the year) it produces small, very fragrant flowers, ranging in color from white to dark purple, gathered in inflorescences with a cymbal-like top. In pot it can grow up to 40-50 cm. both in height and in width; in open ground it reaches 1.5 m. tall and 60-70 cm. in diameter. Several varieties are grown including: "Florence Nightingale", with mauve flowers; "Marguerite", which has white flowers in the center and intense blue-purple in the margins; "Lemoine's Giant", with large purple flowers; "Marina", with blue-violet inflorescences, which reach even 15 cm. in diameter.
Heliotropium arborescens (Berlin Botanical Garden) (website photo)
Environmental requirements, substrate, fertilizations and special precautions
Temperature: the minimum winter temperature must not drop below 7-10 ° C. It does not tolerate frost. To obtain an early flowering, the winter temperature must be raised to 14-16 ° C.
Light: lots of light, even direct sun.
Watering and environmental humidity: water abundantly; the soil must always be kept moist both in summer and in winter.
Substrate: universal soil or fibrous garden soil, which will still be replaced every year in March.
Special fertilizations and tricks: administer liquid fertilizer every ten days during the summer. To obtain an early flowering, the winter temperature must be raised to 14-16 ° C.
Multiplication and pruning
Multiplication: it reproduces by seed, in February, using terrines filled with peat and sand and kept at a temperature of about 15-16 ° C.
New specimens are also obtained by placing, in a cold container at a temperature of 15-16 ° C., Cuttings, obtained from 8-10 cm long twigs. taken in February, July or September.
Pruning: requires pruning of all branches to two thirds or half of their length, to be carried out in March.