Echinocactus grusonii
Synonym: Echinocereus grusonii
Family: Cactaceae​
​Common Name: golden barrel cactus
Origin: Echinocactus grusonii originates from Central Mexico, in the Rio Moctezuma Valley, Queretaro. Its natural habitat includes medium to steep slopes of volcanic rock, 1,400 – 1,900 meters above sea level.
Description: E. grusonii is a solitary cactus, heavily ribbed with sharp orange spines and white wool along the cacti’s crown. When young, the form is globular, becoming elongated with age. During the springtime, and if enough sun is provided, mature specimens may develop a ring of yellow flowers from the head of the cactus.
  • Interesting Features:
    • Although endangered in its natural habitat, E. grusonii will easily naturalize in desert environments.
    • The golden barrel cactus has received the Royal Horticultural Society’s Award of Garden Merit (AGM) for outstanding value in cultivation.
  • Uses: E. grusonii grows toward the south or southwest to avoid the most intense sunlight. As such, this species can be used as a compass by desert travelers.

Cultivation and Care:
  • Watering: Moderate
    • Water moderately from May to September, reducing irrigation in fall for the winter dormancy period.
    • Additionally, watering should only be done at night, to avoid scarring or fungal infection from sunlight.
  • ​Soil: Plant in rich, permeable soil containing clay or sand.
    • Additionally, combine soil with humus, add compost, and maintain a pH between 6.1 and 7.8 to allow species to thrive.
    • For indoor cultivation, fill the bottom of each pot with rocks to ensure sufficient drainage.
  • Lighting: E. grusonii should be given bright sun and direct light, even if grown indoors.
    • While light shade can be provided during high summer temperatures, too much exposure will result in elongated growth and loss of globular shape.
  • Propagation: Although the golden barrel cacti can be propagated from offsets, tubers, rhizomes, and woody stem cuttings, the easiest method is through store-bought seed, sown outdoors in fall.
    • It is recommended to store collected seed in a refrigerator for a year before planting.
  • Cold Tolerance: 20°F, USDA hardiness zones 9a to 11.
  • Special Accommodations: E. grusonii is endangered in its natural habitat – only buy from reputable sellers.
    • During the wintering period, bring cacti indoors and reduce watering, but continue providing bright light.
    • Additionally, to stimulate growth, repot cacti every few years with fresh soil.
    • When handling, wear gloves to prevent damage from the considerable spines.

Sources:
  1. Garden
  2. Gardenia
  3. Dave’s Garden
  4. Monrovia
  5. House Plants Expert
  6. Llifle Encyclopedia of Cacti
  7. Plantopedia
  8. National Parks