Our barrel cactus is flowering! Our barrel cactus in Sunnyvale is 30 years old. It now measures 14 inches wide by 11 inches tall. It started in a 4-inch pot. Echinocactus grusonii, popularly known as the Golden Barrel Cactus is a well known species of cactus, and is endemic to east-central Mexico. The plants do have some basic requirements; an average minimum winter temperature of 12°C (53.6ºF); and good drainage with less watering in winter. Excess water in cool periods may lead to rot. Golden Barrels are hardy to about 15ºF (-8ºC) for brief periods.
Resembling large sewing pincushions, barrel cacti (Ferocactus) offer intimidating spines across a ribbed, spherical body for a home desert landscape. Although barrel cacti may look mundane throughout the year with their basic green bodies and variable spine colors, their blooms burst forth each year with a neon brilliance that is hard to miss. Blooming periods for the barrel cactus range broadly based on local environmental conditions.
Barrel cacti bloom during the spring and summer, typically between April and September. The long daylight hours stimulate the cactus’s body growth, as well as its reproduction. Brightly colored flowers attract bees for pollination; the resulting fruits become food for local wildlife and subsequently spread the cactus’s seed throughout the area. Typically, the fall and winter months are dormant periods for the barrel cactus. Cactus growth halts itself throughout this time period until spring and long daylight hours reappear the next year.
Blooming can be affected by too much or too little sunlight. Barrel cacti must have full sunlight throughout the spring and summer to produce the gorgeous blooms that reside on the top of the plant, but blooming can be stunted when the plant is not properly acclimated to a sunny area. Houseplants placed outside after a shady winter can fail to bloom since they can become sunburned across their green bodies; the plant should be slowly introduced into the sunlight rather than thrust out into 12 hours of constant light. In contrast, a barrel cactus that remains in the shade throughout the entire year does not produce a ring of blossoms that resembles a crown. The cactus may not flower at all or simply produce flower buds without opening.
Cacti are known for their acclimation to drought conditions; their ribs expand with water for storage and contract as the water is consumed throughout the dry period. However, a cactus that has truly shriveled up from lack of water does not have the strength to produce the large blooms; the intricate blossoms require a lot of energy from the plant to cultivate and open. A barrel cactus that retains a normal amount of water from infrequent waterings should be able to bloom within the normal spring and summer periods.
Although acclimating to many soil types, the barrel cactus depends on a well-drained and rich soil structure to produce blossoms. Fertilizing during the growing months with a 5-10-5 ratio mixture will also help amend the soil for spectacular blossoms. The numbers represent the percentages of nitrogen, phosphorus and potassium in the product. The higher phosphorus amount promotes blooms over stem growth. Poor soil nutrients contribute to low blossom output, if any grow at all. Additionally, soils that waterlog the roots also contribute to root rot and blossoming problems; barrel cacti cannot live for very long in wet soil conditions.