Echinocereus coccineus
| Light | Full sun; the more the better, especially outdoors |
|---|---|
| Water | Sparingly in growth; keep bone dry and cold through winter |
| Soil | Very gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Exceptionally cold-hardy when dry; tolerates hard frost, roughly USDA zones 5–10 |
| Propagation | Seed; division of established clumps; offsets |
| Toxicity | Non-toxic to cats and dogs |
Echinocereus coccineus is a clumping, red-flowered hedgehog cactus of the southwestern United States and northern Mexico, closely related to and often confused with the claret cup. Like its relative it is prized for brilliant scarlet flowers and remarkable cold tolerance, and it is commonly known as the scarlet hedgehog. Over time it forms broad mounds of many short stems, making it one of the showier hardy cacti for a rock garden or an unheated greenhouse.
Description
Echinocereus coccineus builds up into dense clumps that may contain anywhere from a few to well over a hundred stems in old plants. The individual stems are cylindrical to shortly columnar, typically 5–25 cm tall, ribbed, and armed with straight or slightly curved spines that vary from pale to dark. Spination is quite variable across its wide range, and populations differ noticeably in stem size, spine colour and density.
The flowers are the main attraction: funnel-shaped, waxy and vivid scarlet to orange-red, borne along the sides of the stems in spring. Unusually for the genus, the blooms do not close fully at night and can last several days. Many populations are functionally dioecious, meaning individual plants tend to be either male or female, so a single clone often sets little or no seed on its own. Red, juicy fruits follow successful pollination, which in habitat is carried out largely by hummingbirds drawn to the red tubular flowers.
Distribution and habitat
The scarlet hedgehog is widespread across the southwestern United States — including New Mexico, Arizona, Colorado and Texas — and extends south into northern Mexico. It grows over a broad range of elevations, from desert grassland up into pinyon–juniper woodland and rocky mountain slopes, where it often nestles among rocks and low vegetation. Because much of its range sits at altitude, the species routinely endures hard winter frosts and snow, which underlies its exceptional hardiness in cultivation.
Cultivation
Echinocereus coccineus is one of the easier hardy cacti to please, provided its two firm requirements are met: strong light and sharp drainage. Grow it in full sun in a very gritty, mostly mineral mix. Through the growing season water thoroughly once the soil has dried, then let it dry again; the clumps can take more water than many desert cacti when in active growth. See Watering for general technique.
The key to its famous cold tolerance is dryness. Kept bone dry from autumn onward, established plants shrug off severe frost and are hardy enough to grow outdoors year-round in surprisingly cold climates. Wet cold, however, causes rot, so gardeners in damp winter regions usually give plants overhead protection or grow them in an unheated greenhouse or cold frame. A cold, dry winter rest also greatly improves spring flowering. See Repotting when a clump outgrows its container.
Propagation
Seed is a reliable method, though because many plants are single-sexed you generally need two clones — a male and a female — flowering together to obtain viable seed. Sow on a warm, gritty surface kept lightly humid; see Propagation — seed. Vegetatively, the species is easily increased by lifting and dividing an established clump, or by detaching rooted offsets from around the base. Allow any cut or broken surface to callus before potting; see Propagation — offsets and Propagation — cuttings.
Common problems
- Rot — the usual cause of loss, from winter wet or a slow-draining mix; stems soften and discolour from the base.
- Etiolation — too little light makes stems thin, pale and elongated instead of stout and well-spined.
- No flowers — often the result of too warm or too wet a winter; the plant needs a genuinely cold, dry rest to bloom well.
- No seed set — expected when only one clone is grown, since many plants are single-sexed.
- Pests — mealybugs (white fluff among the spines and roots) and red spider mites are the usual offenders; see Pests and diseases.
See also
- Echinocereus — the genus overview
- Echinocereus triglochidiatus — the closely related claret cup
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets