Of easy culture, the genus Echinocereus composed of about 70 species native to the southeastern United States and Mexico. The immense variability within a single genus makes the collection of this genus almost unlimited. All temperatures listed are in °Celsius.

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The substrate is draining without completely eliminating organic matter. I give them fertilizer 2x a year at the beginning of summer and at the end of August. In general, watering is stopped in my region at the end of September/beginning of October.

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I distinguish 3 groups to define the hypothetical hardiness according to their origin:

• Baja California: not frost resistant. I keep them frost-free at 2°

• Mexico: hardiness around -8°

• Southwestern USA: generally hardy at -10° and up to -25° 

 

It is worth researching each species and their place of origin and keeping in mind that an arid region can also be very cold in winter. According to Steven Brack, the mountains of New Mexico are a perfect example. -9° in Santa Fe are common in winter. The minima in the mountains go up to -17°. The collection numbers make it possible to know the origin of the plant from a geographical point of view and consequently to deduce the winter temperatures tolerated in the habitat.  Finally, within t the same species, there can be great variability in resistance being the large area of distribution that it can have.

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Another factor is the adaptation of the plant to its growing conditions. A species likeEchinocereus knippelianusv.kruegerigrown from my seedlings and grown outdoors all year round will, I think, have a higher cold hardiness than a mature plant that has never experienced frost placed in frost during a winter.   All the resistances indicated below are given for information only.