Weberbauerocereus weberbaueri
| Light | Full sun to very bright light; acclimatise gradually to avoid scorch |
|---|---|
| Water | Moderate in the warm growing season, letting the mix dry between waterings; keep dry and cool in winter |
| Soil | Fast-draining mineral-rich mix (see Soil and potting mix) |
| Temperature | Best above freezing; tolerates brief light frost when bone dry, roughly USDA zones 9b–11 |
| Propagation | Seed; cuttings of branches or offsets |
| Toxicity | Not known to be toxic to cats or dogs |
Weberbauerocereus weberbaueri is a tall, branching columnar cactus native to the arid mountains and river valleys of southern Peru. It is prized by growers for its dense, golden-brown spines, which sheathe the stems in a warm glow, and for its slender, pinkish, night-to-dawn (crepuscular) flowers, making it a striking specimen in both landscape plantings and pot culture. It is the type species of the genus Weberbauerocereus.
Description
Weberbauerocereus weberbaueri is a large columnar cactus that branches from the base and lower stem, in time building into a shrubby or small tree-like clump of erect stems. Individual stems are ribbed and, in habitat, can reach several metres tall, though potted plants stay far smaller and slower. Each rib carries closely set areoles bristling with numerous fine, needle-like spines that range from pale amber to rich golden-brown, ageing greyer with time. The dense spination gives mature stems a soft, hairy-golden look and helps shade the body from the fierce high-altitude sun.
The flowers are narrow and tubular and vary considerably in colour, from whitish through pink to reddish. They open in the evening and remain open through the night into the early morning — a crepuscular habit that, in the wild, allows pollination by both bats and hummingbirds. Elongated fruits follow.
Distribution and habitat
The species is native to southern Peru, where it grows on rocky slopes, canyon walls and the terraces of dry river valleys on the arid western Andean slopes, at roughly 1,700–3,100 m elevation. It is well adapted to intense sunlight, sharp drainage and long dry spells punctuated by seasonal moisture, sharing this harsh terrain with other columnar cacti and desert scrub.
Cultivation
Weberbauerocereus weberbaueri is a robust and rewarding grower given the two things it most wants: strong light and excellent drainage. Plant it in a gritty, mostly mineral mix and give it the sunniest position available; in weaker light the golden spination is sparser and the growth softer and more prone to problems. Because plants grown under glass have not built up sun-hardened tissue, increase exposure gradually in spring to avoid scorching.
Water moderately through the warm growing season, letting the mix approach dryness between soakings, then keep the plant dry and cool over winter to firm it up and reduce the risk of rot. As a vigorous columnar species it appreciates room for its roots; see Repotting and Watering for general technique. In frost-free climates it makes an excellent, low-fuss landscape plant.
Propagation
Both seed and vegetative methods work well. Seed germinates readily on a warm, moist mineral surface and is the usual way to raise numbers of plants; see Propagation — seed. Branches and basal offsets can also be removed and rooted as cuttings — allow the cut surface to callus for a week or more in a dry, shaded spot before setting the piece on barely-moist, gritty mix to root.
Cultivation uses
Beyond the collector's bench, W. weberbaueri is valued as an ornamental and structural landscape cactus in dry gardens, where its columnar habit and warm golden spines add strong vertical form.
Common problems
- Rot — the main killer, almost always from overwatering or a slow, water-retentive mix, especially in cool weather; stems soften and discolour from the base.
- Etiolation — too little light produces pale, thin, weakly spined growth that loses the species' dense golden character.
- Pests — mealybugs (white fluff among the spines and at the roots) and red spider mites (fine webbing and bronzed tissue) are the usual offenders; see Pests and diseases.
See also
- Weberbauerocereus — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings · Repotting