Kroenleinia grusonii
golden barrel cactus
Overview
Kroenleinia grusonii, long known as Echinocactus grusonii, is a barrel-shaped cactus in the family Cactaceae, native to a small area of central Mexico. Young plants are nearly spherical and become barrel- to column-shaped with age, reaching 2-3 feet (60-90 cm) tall and 16-32 inches (40-80 cm) wide over many decades. The body is bright green with 20-35 prominent vertical ribs lined with stiff, golden-yellow spines 1-1.25 inches (2.5-3 cm) long, and a dense cap of woolly hairs and yellow spines at the crown. Plants more than about 20 years old produce yellow flowers 1.5-2 inches (4-5 cm) across in a ring around the crown in summer, opening only in strong sun. It grows on rocky volcanic slopes in a largely frost-free climate and is endangered in the wild, though widely propagated in cultivation. It is slow-growing and intolerant of wet, cold soils, which cause rot at the base. Plants offset slowly and may form small clusters with great age.
Native Range
Kroenleinia grusonii is native to a limited area of east-central Mexico, in the states of Queretaro and Hidalgo, where it grows on rocky volcanic slopes. Its wild range is small and the species is endangered in habitat, with much of its former range lost to a reservoir.Suggested Uses
Kroenleinia grusonii is used as a specimen in desert and rock gardens, gravel beds, and containers, and in dry, low-water landscapes. It suits hot, sunny spots with sharp drainage. In cold or wet climates it is grown in pots that can be sheltered in winter.How to Identify
Appearance
Size & Dimensions
Height2' - 3'
Width/Spread1'4" - 2'8"
Bloom Information
Yellow flowers 1.5-2 inches (4-5 cm) across open in summer (June-August) in a ring around the woolly crown, but only on plants more than about 20 years old. Each flower opens in strong sunlight and lasts a few days. Flowering is sparse relative to the size of the plant.
Detailed Descriptions
Foliage Description
bright green stem with golden-yellow spinesGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Kroenleinia grusonii grows in full sun and fast-draining, gritty or sandy mineral soil with little organic matter. It is drought tolerant and needs watering only when the soil has dried fully, with water reduced to almost none in winter. It is hardy to about 20F (-7C) for short periods, roughly USDA zones 9-11, and cold, wet conditions cause rot at the base. Grow it in a container of cactus mix in climates with cold or wet winters so it can be moved under cover. It grows slowly, adding little size each year, and takes many years to reach flowering size. Strong sun all year keeps the spines dense and the body firm.Pruning
Cacti are not pruned. Damaged or rotted tissue can be cut out with a clean blade and the cut left to dry, and offsets can be removed at the base if separate plants are wanted.Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons