Neobuxbaumia tetetzo
| Light | Full sun; give as much bright light as you can |
|---|---|
| Water | Sparingly in growth, allow to dry fully between waterings; keep dry and cool in winter |
| Soil | Very free-draining mineral mix (see Soil and potting mix) |
| Temperature | Warmth-loving; protect from frost, roughly USDA zones 9b–11 |
| Propagation | Seed (primary); cuttings possible but slow to root |
| Toxicity | Not known to be toxic to cats or dogs; spines are the main hazard |
Neobuxbaumia tetetzo is a tall, grey-green columnar cactus native to south-central Mexico, where it forms vast, cathedral-like stands of upright columns across the arid Tehuacán–Cuicatlán Valley. Locally it is known as tetecho or tetetzo, and its dense forests are one of the signature landscapes of the region. It belongs to the genus Neobuxbaumia, a group of stately Mexican columnar cacti.
Description
Neobuxbaumia tetetzo is a large, tree-like cactus that grows as a tall column. Young and middle-aged plants are typically unbranched, but old individuals may fork and put out branches, sometimes carrying many erect arms. Mature plants reach many metres in height — up to around 15 m in the largest old specimens — giving them the look of slender grey-green pillars rising above the scrub. The stem is stout and firm, divided into many closely set vertical ribs.
The areoles run in neat rows along the rib crests and carry stiff spines. The stems themselves are a glaucous grey-green, so that from a distance the whole column reads as a soft, dusty green rather than an obviously spiny plant. Flowering occurs from the upper part of the stem: the flowers are relatively small for so large a cactus, bell- to funnel-shaped and pale (whitish to greenish), opening at night. As in many big columnar cacti they are visited and pollinated by bats and other nocturnal animals, and are followed by fleshy fruits that local wildlife readily eats.
Distribution and habitat
The species is endemic to south-central Mexico, centred on the Tehuacán–Cuicatlán Valley spanning parts of the states of Puebla and Oaxaca. There it is a dominant, forest-forming plant of the semi-arid thornscrub, growing on rocky slopes and well-drained valley floors alongside other columnar cacti and drought-adapted shrubs.
These tetecho forests are ecologically important, providing shade, roosting and nesting sites, and food for birds, bats and other animals. The plants tolerate strong sun, high daytime heat and long dry spells, drawing on infrequent seasonal rains.
Cultivation
Neobuxbaumia tetetzo is grown by collectors of columnar cacti and, in suitable warm, dry climates, as an imposing landscape plant. It asks for the same basic treatment as most desert columnar species: a very free-draining, largely mineral mix, the brightest position available, and careful watering — a good soak once the soil has dried right out during the warm growing season, then a dry, cool rest through winter.
The chief risk in cultivation is rot from staying wet, so err on the side of underwatering, especially in cool weather. Plants are slow but steady, and young specimens appreciate warmth to keep them moving. In pots the species will remain far smaller than its wild dimensions for many years; large plants eventually need a heavy, stable container and periodic repotting into fresh gritty mix. Frost protection is essential outside frost-free areas.
Propagation
Seed is the standard and most reliable method. Sow onto a warm, moist mineral surface and keep humid until the seedlings establish; growth is slow at first, as is typical for large columnar cacti. See Propagation — seed for general technique.
Large columns can in principle be propagated from stem cuttings, but sizeable pieces are unwieldy and can be slow and reluctant to root, so cuttings are far less common than seed for this species.
Common problems
- Rot — the usual cause of loss, almost always from overwatering, a poorly draining mix, or cold-and-wet conditions; the stem softens and discolours.
- Etiolation — too little light produces thin, pale, weak growth that never develops the sturdy character of a sun-grown plant.
- Pests — mealybugs (white fluff in the areoles and at the roots) and scale are the most likely nuisances; see Pests and diseases.
- Cold damage — frost scars or kills exposed tissue, so unprotected plants should not be left out through freezing weather.
See also
- Neobuxbaumia — the genus overview
- Tehuacán–Cuicatlán Valley
- Soil and potting mix · Watering · Repotting · Propagation — seed · Propagation — cuttings · Pests and diseases