Espostoa lanata
| Light | Bright light to full sun; a little shade from the harshest afternoon sun when young |
|---|---|
| Water | Moderately in growth, allowing the mix to dry between waterings; keep nearly dry in winter |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; happiest in USDA zones 9b–11 |
| Propagation | Seed; sometimes cuttings from branched or offsetting plants |
| Toxicity | Non-toxic to cats and dogs |
Espostoa lanata, the Peruvian old man cactus, is a white-woolly, columnar cactus from the dry valleys of Peru and Ecuador and one of the most widely grown members of the genus Espostoa. Its green stem is wrapped in a dense veil of long, silvery-white hairs that give mature plants their shaggy "old man" look, hiding sharp spines beneath the wool.
Description
Espostoa lanata is a slow-growing columnar cactus that becomes tree-like with great age, eventually branching from the base or lower stem to form a candelabra of upright columns a few metres tall in habitat. In cultivation it is usually seen as a single erect column, ribbed and clothed all over in soft white hair produced from the areoles. Beneath that woolly coat sit fine yellowish to reddish spines, so the fluffy surface is less friendly to bare hands than it looks.
As plants mature they develop a cephalium — a dense, wool-and-bristle flowering zone that forms along one side of the stem. Nocturnal, funnel-shaped flowers in white to purplish emerge from this cephalium and are followed by small fleshy fruits. Reaching flowering size takes many years, so most collected plants are grown simply for their handsome silvery columns.
Distribution and habitat
The species grows on arid slopes and in seasonally dry valleys of the Andes in northern Peru and southern Ecuador, typically at moderate elevations. There it experiences strong sun, warm days and cooler nights, and long dry spells broken by seasonal rain. The thick coat of white hair is thought to help shade the stem from intense high-altitude sunlight and buffer it against temperature swings.
Cultivation
Espostoa lanata is one of the more forgiving hairy cacti and a good choice for a grower ready to move beyond the easiest beginner plants. Give it the brightest spot you can — plenty of direct sun keeps the wool dense and white, while too little light produces sparse hair and weak, etiolated growth. Grow it in a very free-draining, mostly mineral mix and water moderately through the warm months once the mix has dried, then keep it nearly dry and cool over winter to prevent rot and preserve the plant's shape.
Take care when watering overhead, as water trapped in the wool can encourage discolouration; watering the soil rather than the plant keeps the coat looking its best. See Watering and Repotting for general technique, and handle the plant with folded paper or gloves, since the soft-looking hairs conceal spines.
Propagation
Seed is the usual way to raise Espostoa lanata. The seeds germinate well on a warm, mineral surface kept humid and lightly shaded, though seedlings are slow and take time to develop their characteristic wool. Where a plant has branched or produced offsets, stem cuttings can be taken, allowed to callus thoroughly, and then rooted in a gritty mix; this is less common but useful for multiplying a favourite plant. See Propagation — seed and Propagation — cuttings for full walkthroughs.
Common problems
- Rot — usually from overwatering, a slow-draining mix, or a cold wet winter; the stem softens and discolours, often from the base.
- Discoloured or matted wool — caused by hard water, dust, or repeated overhead watering; the white coat yellows or clumps and is slow to recover.
- Etiolation — too little light makes the column thin and pale with noticeably thinner hair.
- Pests — mealybugs love to hide within the wool where they are easily missed, and red spider mites can bronze the stem; inspect the hairy areoles regularly. See Pests and diseases.
See also
- Espostoa — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Propagation — cuttings · Pests and diseases