Ricinus communis Zanzibarensis seeds - Castor Bean

The Zanzibar castor bean (Ricinus communis 'Zanzibarensis') is a spectacular exotic plant, perfect for adding a tropical touch to the garden. Its oversized foliage, composed of large palmate leaves, along with its rapid growth, make this plant a must-have for lush flower beds. When planted in the ground, this castor bean can reach up to 2.50 m in height in a single season. Planted in a large pot, it transforms terraces and balconies. Not frost-hardy, this castor bean is grown as an annual in temperate climates. Sow in spring, under cover from March or directly in the ground after the last frosts.

Ricinus communis 'Zanzibarensis' belongs to the Euphorbiaceae family. Native to tropical Africa, particularly Ethiopia, Eritrea, and Somalia, the species Ricinus communis has become naturalized in many tropical and subtropical regions worldwide. The 'Zanzibarensis' cultivar was introduced in 1870. It stands out for its more imposing size and highly ornamental foliage. This shrubby plant has an upright habit and extremely rapid growth. In the ground, it can reach a height of 2 to 3 m in a single season in temperate climates, and up to 4 m under optimal conditions. When grown in pots, its size is generally more modest, ranging between 1.5 and 2 m. The leaves, with an impressive diameter of 60 to 90 cm, are palmate with 5 to 12 toothed lobes. They are green, accentuated by whitish veins, with a reddish margin. The robust, thick, and hollow stems can be green or reddish. Flowering occurs in summer, between June and August. The inflorescences in clusters are located at the top of the stems. The male flowers, situated at the base of the inflorescence, feature prominent pale yellow stamens, while the female flowers, positioned at the top, have distinctive red pistils. Pollination is primarily anemophilous (wind-dependent), though insects may also contribute. The fruits are spherical tricoccous capsules, bristly with spines, measuring about 3 cm long and 1.6 cm wide. When ripe, these capsules release ovate, glossy seeds, marbled with red or brown, containing 40 to 60% oil rich in triglycerides, mainly ricinolein. All parts of the plant, especially the seeds, are highly toxic if ingested.

Historically, the castor bean has been used since antiquity, notably by the Egyptians, for extracting its oil with purgative and cosmetic properties. Despite its toxicity, castor oil is employed in various applications, from traditional medicine to the production of lubricants and cosmetic products.

The 'Zanzibarensis' castor bean, with its lush vegetation, is particularly prized for adding an exotic and tropical touch to gardens and green spaces. It quickly fills a garden corner at little cost, guaranteeing a striking display. To create a perfectly exotic setting, plant a Chinese windmill palm Trachycarpus fortunei and a Japanese banana (Musa basjoo) as a backdrop. Pair it with large, colourful cannas such as 'Marabout'.