Opuntia sulfurea White - Prickly Pear

The 'Opuntia sulfurea 'blanc' is a beautiful form with white translucent flowers of the Opuntia sulphurea. It is a very rare cactus in cultivation that will delight collectors. Apart from flowering, this prickly pear is characterized by the unusual appearance of its pads, elongated oval in shape, very thick, they have an embossed pattern from which long red-ringed prickles and crenulated margins emerge. The plant is more or less sprawling, well-branched, of medium vigor, and easy to grow in full sun in any well-drained, poor, rocky, and arid soil, in the ground in our regions that are not too cold and not too humid in winter. It will also make a big impression in a pot on the terrace, placed far from foot traffic!

The Opuntia sulphurea, a close relative of the Prickly Pear (Opuntia ficus indica), is a succulent plant devoid of true leaves from the cactus family. This botanical species is native to the dry areas of northern Argentina. It forms a bush that is wider than it is tall, an adult plant will reach about 40-50 cm (16-20in) in height and can spread laterally up to an average of 1.50 m (5ft). Its dimensions will of course be reduced in a pot. Its growth is moderately fast, with the plant producing 1 or 2 generations of new pads per year from spring to autumn. The vegetation is composed of pads or cladodes that are stacked on top of each other. Measuring up to 10-15 cm (4-6in) wide and 30 cm (12in) long, with a thickness of 3 to 7 cm (1 to 3in), they are obovate to oblong in shape and fleshy. The base of the plant lignifies with age, forming a very short trunk. The green surface of the pads is covered with white-gray areoles adorned with tiny transparent but formidable spines called glochids, from which clusters of white prickles emerge, measuring up to 10 cm (4in) long, irregularly ringed with reddish-brown. On the young pads, succulent and curled atrophied leaves appear, which quickly disappear in favor of the glochids and prickles. Flowering occurs from late May to late July, earlier or later depending on the climate. Several flowers appear around the edges of the pads, mainly towards their tips. The cup-shaped flowers, 4 cm (2in) wide, are composed of shiny white petals with a fine and slightly translucent texture. In favorable climates, they give way to small pear-shaped fruits that turn reddish when ripe.

This surprising Prickly Pear is hardy down to -10°C without protection, but in perfectly drained, rocky, or sandy soil. It must be planted in a rock garden or on a dry slope, mainly in hot and dry regions in summer. It naturally structures exotic or contemporary landscapes, associated with hardy agaves, Nolinas, and arborescent Euphorbias. In cold and humid climates, it can be easily grown in a pot, allowing it to be sheltered in winter in a cold greenhouse or an unheated conservatory, kept almost dry.