Ferocactus glaucescens, commonly known as the blue barrel cactus, is a succulent plant native to the arid limestone hills of Hidalgo in central Mexico. This cactus typically forms a spherical to cylindrical shape and can reach up to 60 cm (24 in) in diameter. It is characterized by its glaucous (blue-green) stem and long yellow spines that provide a striking contrast. The blue barrel cactus blooms with showy yellow flowers in the summer, which are followed by yellow fruits.

In cultivation, Ferocactus glaucescens is valued for its drought tolerance and unique appearance, making it a popular choice for rock gardens, desert landscaping, and as a potted specimen in temperate regions where it must be grown under glass to protect it from cold temperatures. It thrives in full sun, requiring very low amounts of water, and prefers well-draining soils, typically those that are sandy or gravelly. While it is slow-growing, it is relatively easy to maintain and has been recognized with the Royal Horticultural Society’s Award of Garden Merit. Gardeners should be cautious of its sharp spines when handling.CC BY-SA 4.0