- Barrel cactus plant
- Cactus/succulent potting mix
The aptly named golden barrel cactus (Echinocactus grusonii) is now quite rare in its native habit, but it is frequently grown in cultivation as a houseplant. Less frequently, is is used in the outdoor garden in dry climates where temperatures never fall below 40 degrees Fahrenheit (zone 10 and 11). However, the cactus is less likely to flower indoors than when it's grown in a garden or yard. Amusingly, this prickly plant's nickname is "mother-in-law cushion."
Barrel cacti, as the name implies, are almost perfectly round when juvenile, so they make excellent display plants. They are highly attractive, with the evenly spaced rows or 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), but they grow very, very slowly, so indoor specimens will remain manageable for many before becoming a problem.
|Botanical Name||Echinocactus grusonii|
|Common Names||Golden barrel cactus, mother-in-law's cushion|
|Plant Type||Perennial cactus|
|Mature Size||About 3 1/2 feet in height, 2 feet in spread (very slow growing)|
|Sun Exposure||Full sun|
|Soil Type||Dry, well-drained soil, or cacti/succulent potting mix|
|Soil pH||6.1 to 7.5 (slightly acid to slightly alkaline)|
|Bloom Time||Summer (does not bloom until the plant is quite old)|
|Hardiness Zones||Zones 10 to 11 (USDA)|
|Native Area||Rocky volcanic slopes of Mexico, SW United States|
How to Grow Golden Barrel Cactus
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 a 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.
A barrel cactus does best in a very sunny window, perhaps a southern exposure. Plants that do not get enough sunlight will grow slowly and fail to thrive. Outdoors, grow it in a full-sun location, though it will also tolerate some shade.
A cactus soil mix is ideal. If you use a regular peat-based mix, be sure to add sand or extra perlite to enhance drainage. Repot the plant when the soil begins to break down. Encourage drainage by adding a few inches of gravel or small pebbles to the bottom of the pot. When grown outdoors, this plant needs a dry, very well-drained soil.
Water infrequently (every month or two) and ensure that the soil drains completely. Do not leave any water sitting in the tray or allow them to sit in water. Golden barrel cacti are very prone to root rot.
Temperature and Humidity
While the plant favors warm, dry conditions, the cactus can tolerate temperatures down to 40 degrees Fahrenheit. It does best without humidity, but should be just fine in a regular household environment.
Feed these plants every four weeks with a high-potassium fertilizer.
Potting and Repotting
Barrel cacti should be repotted every few years. It's best to repot at the beginning of the growing season, or in summer. To repot a cactus, make sure the soil is dry, then gently extract the plant from the pot while wearing thick leather gloves. Knock away the old soil from the roots, making sure to remove any rotted or dead roots in the process. Treat any cuts with a fungicide.
Place the plant in its new pot and backfill with potting soil designed for cacti, spreading the roots out as you repot. Leave the plant dry for a week or so, then begin to water lightly to reduce the risk of root rot.
Propagating Golden Barrel Cactus
Barrel cactus is typically propagated by seed. A mature cactus will bloom in the summer with flowers that grow in whorls around the top of the plant. To seed a cactus, plant the seeds shallowly in a cactus mix and keep them warm and very slightly moist.
Barrel cacti may also sprout "pups" at the base of the plant. Remove the soil from around the baby plant then slice it away from the mother plant using a sharp knife. Let the pup sit for a day or so until the cut area forms a slight callus, then plant it in a container filled with coarse cactus-mix potting soil. Water immediately, but then limit water until the new plant roots itself.
Golden Barrel vs. Other Barrel Cacti
There are several species of Echinocactus that go by the common name barrel cactus. They may be hard to find in nurseries but are easy enough to grow from seeds purchased from online specialty retailers.
- California barrel (Ferocactus cylindraceus) is known as California barrel cactus, desert barrel, or miner's compass. It is a tall variety with yellow flowers and downward-curving spines.
- Fishhook cactus (F. wislizenii) is known as Arizona barrel cactus, candy barrel cactus, or Southwestern barrel cactus. It has more colorful flowers than other species of barrel cactus.
- Blue barrel (F. glaucescens) is commonly called glaucous barrel cactus or Texas blue barrel. It has blue-green stems and long-lasting lemon-yellow flowers.
- Colville’s barrel (F. emoryi) is commonly known as Emory’s cactus, Sonora barrel, traveler’s friend, or nail keg barrel. It has spines that may turn gray or pale gold as the plant matures. The flowers are yellow, orange, or maroon.
Common Pests/ Diseases
Problems with a golden barrel cactus are rare, but occasionally they may become infested with mealybugs or scale. Spraying with water, then coating with insecticidal soap is the best remedy.
The spines are golden barrel cactus are very sharp, so this plant poses some danger in a home with pets or children. Keep this plant out of high-traffic areas where you might accidentally brush against it.