Opuntia robusta or Wheel cactus

Care of the cactus Opuntia robusta or Wheel cactus

The genus Opuntia, family Cactaceae, includes some 300 species of cacti originating in Mexico, the USA and Central and South America. Some species are: Opuntia robusta, Opuntia polyacantha, Opuntia microdasys, Opuntia linguiformis, Opuntia leucotricha, Opuntia engelmannii, Opuntia bergeriana, Opuntia santa-rita, Opuntia rufida, Opuntia ficus-indica, Opuntia durangensis, Opuntia subulata, Opuntia atrispina, Opuntia phaeacantha, Opuntia valida, Opuntia macrocentra, Opuntia chlorotica, Opuntia auberi, Opuntia lindheimeri, Opuntia vestita, Opuntia spinulifera.

Common names: Wheel cactus, Wheel pear, Silver Dollar Prickly Pear, Nopal tapon. Scientific synonyms: Opuntia camuessa, Opuntia gorda. This species is native to northern and central Mexico.

They are shrubby cactus (sometimes arboreal) that reach 3 meters (9.84 feet) in height. The large segments up to 40 cm (15.74") thick, oval or circular are bluish-green or grayish in color. The areolas are white or yellowish in color and have 2-12 spines. The showy, abundant yellow flowers bloom from late spring to late summer. They produce edible ovoid fruits.

They are used to form groups, in rockeries, as screens and as isolated specimens. If they are grown in pots they grow and flower less.

Opuntia robusta needs full sun exposure and warm climates. In winter the temperature should not be lower than 7 ºC (44.6 ºF).

They grow in any type of well-drained soil, even in poor and sandy substrates. The pot transplant is done in early spring.

They resist drought well but appreciate frequent watering in summer, always waiting for the substrate to dry. Do not water in winter.

Fertilize with mineral cactus fertilizer once in early spring and again in early summer.

Prune in spring to control development or to remove dry segments.

They are sensitive plants to excess humidity and to the attack of mealybugs, especially young specimens.

They are easily propagated from segment cuttings rooted in slightly damp sandy soil and previously dried for 2 weeks in a ventilated place without direct sun. The seeds take up to 1 month to germinate.