The Golden ball (Echinocactus grusonii) is now quite rare in its native habit, but it is frequently grown in cultivation as a houseplant. Less frequently, it is used in the outdoor garden in dry climates where temperatures never fall below 40 degrees Fahrenheit. However, the cactus is less likely to flower indoors than when it’s grown in a garden or yard. If it does bloom, flowers come in the spring.
Also known as a barrel cacti, as the name implies, they are almost perfectly round when juvenile, so they make excellent display plants. They are highly attractive, with evenly-spaced rows of spines on their deeply ribbed lobes. As they grow, it’s not uncommon for them to stretch out so they are more oval than circular. As with most cacti, the secret to successful indoor growth is nearly perfect drainage, as opposed to letting them dry out.
This can be quite a large plant when fully mature (as much as 6-feet tall), but they grow very, very slowly, so indoor specimens will remain manageable for many before becoming a problem. The genus Echinocactus includes about six species of barrel cacti, including the golden variety, native to Mexico and the southwestern United States. These are true desert plants that cannot handle standing water when growing. Plant them in very well-draining soil or potting mix, and water no more than once a month. When grown indoors, these plants will need the brightest, sunniest location you have.