Echinocereus (echi-no-ce-re-us) is a very popular genus of cacti due to their easy to manage size and shape. Many barely get a foot tall and fewer still get wider than 4". Between that and their surreal flowers, it's no wonder Echinocereus plants end up in many cactus collections.
Form: These plants generally form short, skinny columns with few exceptions. Most produce offsets from their base and some can form clumps, albeit slowly. They vary dramatically in spine color and length but all of them bare their spines on ribs.
Colors: Their stems are lime green nearly without exception. However, their spines can vary from white to yellow to black.
Foliage: The foliage of all of these plants are organized into spines. None produce photosynthetic leaves.
Flowers: Some of the most gorgeous in the cactus family. They're frequently wider than the plant they're borne on and they're frequently two toned. Their floral tubes are spined to protect the delicate petals.
Light: They prefer full sun conditions as this encourages spine growth and flowering.
Soil: Pick a gritty, well-draining mix like a cactus and succulent soil (available at garden centers) or mix your own (more info).
Water: Water deeply enough for water to run out the container’s drainage hole. Allow soil to completely dry before watering again. Keep dry in winter.
Hardiness:Echinocereus are generally not frost hardy and should be brought indoors to a sunny window sill if there is a chance of frost. (What’s my zone?). However, there are a few exceptions to this rule.
Propagation: Most produce new offsets around their bases and can root from stem cuttings (use gloves to avoid contact with spines). They can also be grown from seed.
NOTES FROM THE NURSERY
Echinocereus has a very large range compared to many other genera of cacti. Species from this genus can be found growing in southern Mexico while other species can be found growing as far north as South Dakota, USA. Some prefer low elevations while others can be found at 8000 feet. Needless to say, they are survivors.
This variation in range directly correlates to variation in structure and, as such, it's difficult to put them all in one group. This variation even applies at the species level and very different looking plants can find themselves in the same species. This makes ID difficult so be sure not to lose your nursery label!