Pediocactus peeblesianus
| Light | Bright light with airy conditions; some protection from the most intense summer sun |
|---|---|
| Water | Very sparingly; keep bone dry through a long, cool winter rest |
| Soil | Extremely fast-draining, gritty mineral mix (see Soil and potting mix) |
| Temperature | Cold-hardy when dry; tolerates hard frost in habitat, USDA zones 5–9 |
| Propagation | Seed; often grafted as young seedlings to improve survival |
| Toxicity | Not known to be toxic to cats and dogs |
Pediocactus peeblesianus is a tiny, cold-hardy cushion cactus native to northern Arizona, and one of the more challenging North American cacti to keep alive in cultivation. It is best known through its variety Pediocactus peeblesianus var. peeblesianus, the Peebles Navajo cactus, which is federally listed as endangered in the United States — meaning every legitimate plant in the hobby is nursery seed-grown, never wild-collected. The species belongs to the small, demanding genus Pediocactus of the high deserts and plateaus of the American West.
Description
Pediocactus peeblesianus is a diminutive, usually solitary cactus whose grey-green to brownish body sits low and flattened, often no more than a few centimetres across. The small tubercles carry short, weak spines that vary between the varieties — from nearly absent to a scatter of pale, spreading radials — and the plant can pull down almost flush with the soil surface during drought.
Flowers appear in early spring, relatively large for so small a body, in soft shades of yellow, cream or pale green. Like others in the genus, it spends much of the year shrunken and inconspicuous, blending into the gravel and sparse vegetation of its home ground and only swelling and flowering during the brief window of favourable weather.
Distribution and habitat
The species is endemic to northern Arizona, growing on open, gravelly flats and low limestone or sandstone hills within the range of the Colorado Plateau. Var. peeblesianus in particular occupies a very restricted area near the Little Colorado River, on sparse, well-drained soils among scattered desert scrub.
These are continental high-desert habitats: hot, dry summers and genuinely cold winters with frost and occasional snow. The plants endure this by staying almost completely dry when cold, a fact that dictates everything about how they must be grown.
Cultivation
Pediocactus peeblesianus has a reputation as a difficult subject, and it is not a plant for beginners. The two great enemies are moisture and heat while dormant. Grow it in an extremely gritty, almost entirely mineral mix in a deep pot, in bright light with excellent airflow, and water only lightly during its active growth in spring and autumn.
Through winter — and equally through the hottest part of summer, when the plant naturally rests — keep it dry. Many growers find it far easier to maintain on its own roots in a cold, unheated frame that mimics the plant's natural dry-cold cycle than in a warm, humid greenhouse where rot sets in quickly. Because own-root plants are slow and touchy, grafting young seedlings onto a hardier rootstock is a common way to establish them; grafted plants grow faster but look less natural. See Watering and Repotting for general technique.
Propagation
Seed is the standard and, for conservation reasons, the only appropriate method. Germination can be slow and erratic, and the tiny seedlings are vulnerable, so many growers graft them early to carry them through the difficult first stages before returning them to their own roots. The species rarely offsets, so vegetative increase from the wild-type plant is uncommon. See Propagation — seed for a full walkthrough.
Common problems
- Rot — by far the biggest killer, caused by watering while the plant is dormant, cold or hot; the body softens and collapses from the base.
- Loss during dormancy — plants kept too warm and moist over winter fail to rest properly and decline.
- Pests — root mealybugs are a particular threat to this genus and should be watched for at every repotting; see Pests and diseases.
Legal status
Pediocactus peeblesianus var. peeblesianus, the Peebles Navajo cactus, is listed as an endangered species under the U.S. Endangered Species Act, and — like the entire cactus family — the genus is covered by CITES. Collecting, digging, or removing plants from the wild is prohibited, and its very limited range makes wild populations especially fragile.[1]
Importantly, this protection is a matter of conservation, not of any psychoactive property: Pediocactus cacti are not sources of mescaline or other notable alkaloids, and the restrictions exist solely to protect a rare, slow-growing plant from extinction. Nursery-propagated, seed-grown plants of legal origin are the only ones that should ever change hands, and buyers should ask sellers about provenance. When acquiring plants, choose material that is clearly documented as cultivated rather than wild-collected.
See also
- Pediocactus — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — seed · Pests and diseases
References
- ↑ U.S. Fish & Wildlife Service, Endangered Species listing for Pediocactus peeblesianus var. peeblesianus.