Echinocactus (Cactaceae) Echinocactus has around six species of cactuses, from southwestern North America. Echinocactus grusonii This barrel-shaped cactus from central Mexico is often grown for its golden spines and large stem, 80cm (32in) in diameter. Yellow flowers, to 6cm (2½in) long and 5cm (2in) across, appear in summer. Cultivation Needs sandy rocky soil. Water infrequently, mostly in spring. Height to 1.3m (4ft); spread to 1m (3ft). USZ 10–11, surviving -1°C (30°F) of overnight frost. Tolerant of summer drought. |