Spacing: 6-9 in. (15-22 cm) 9-12 in. (22-30 cm) 12-15 in. (30-38 cm) 15-18 in. (38-45 cm)
Hardiness: USDA Zone 9b: to -3.8 °C (25 °F) USDA Zone 10a: to -1.1 °C (30 °F) USDA Zone 10b: to 1.7 °C (35 °F) USDA Zone 11: above 4.5 °C (40 °F)
Sun Exposure: Full Sun Sun to Partial Shade Light Shade
Bloom Color: Pale Yellow Bright Yellow
Bloom Time: Mid Summer Late Summer/Early Fall Mid Fall
Foliage: Silver/Gray Succulent Rubbery-Textured
Other details: This plant is suitable for growing indoors Drought-tolerant; suitable for xeriscaping Average Water Needs; Water regularly; do not overwater This plant may be considered a protected species; check before digging or gathering seeds
Soil pH requirements: 6.1 to 6.5 (mildly acidic) 6.6 to 7.5 (neutral) 7.6 to 7.8 (mildly alkaline)
Patent Information: Non-patented
Propagation Methods: From seed; winter sow in vented containers, coldframe or unheated greenhouse From seed; sow indoors before last frost From seed; direct sow after last frost
Seed Collecting: Collect seedhead/pod when flowers fade; allow to dry Allow unblemished fruit to ripen; clean and dry seeds Properly cleaned, seed can be successfully stored
On Oct 15, 2011, Bronto from Scottsdale, AZ wrote:
The Bishop's cap cactus seems virtually indestructible in a pot indoors, or outside in soil or pot with good drainage in warm/desert climate. A great plant for novice cactus enthusiast, will survive well indoors in sunny window, leave mostly dry in cold weather. A potted specimen moved from LA to a pot in Alaska, into the ground in Arizona, and then into a pot again has survived for over 25 years, and is now 18" in height. It has not been repotted in 10 years.
On Mar 18, 2008, palmbob from Tarzana, CA (Zone 9b) wrote:
In my garden this is one of the easiest and hardiest cactus to my forms of abuse I own. I have about 10 of these now, and they survive all sorts of random watering strategies, bright, searing hot, full day sun (got to 120F few years ago and didn't affect these), and down to 25F with no damage... and some live in almost total shade (no direct sunlight at all) and do fine. All live outdoors and get drenched all winter long by our cold rains here in southern California, and to no ill effects whatsoever (though most cacti tolerate our freezing cold rains for some reason despite everyone's recommendations to keep them dry in winter). Never had one of these rot. The move easily, have no spines, look great all year round in any condition... just about one of the most perfect cacti you can grow I think.
On Nov 30, 2002, philomel from Castelnau RB Pyrenées France (Zone 8a) wrote:
This plant has showy yellow flowers between June and September. However, the rest of the year it gives pleasure from its interesting form and texture.
It should be kept dry over winter.
This plant has been said to grow in the following regions:
Grenoble, Maricopa, Arizona Phoenix, Arizona Picture Rocks, Arizona Scottsdale, Arizona Sun Lakes, Arizona Tucson, Arizona Brea, California Carlsbad, California Castro Valley, California Perris, California Reseda, California San Diego, California Palacios, Texas