It begins with the soil mix which must be coarse and gritty. I usually use small gravel gathered from mountain river beds, perlite, volcanic rocks, granite chippings, coco choir and worm casts - produced in the house. I keep mature specimens in full sun, with no shade, even when temps are above 40ºC. Waterings are done twice a month or so, with rain water only. If kept in the same pot for several years, I usually sprinkle some fresh worm castings on top once a year as seen in the picture above. Other diluted nutrients are used very rarely and only if organic, with low N values and high PK.
During dormancy I stop watering completely and keep them in a dry and well illuminated environment - natural light only. Temperatures may drop below freezing point with no consequences whatsoever.
The specimen in the pictures is the El Huizache variety originally from San Luis Potosi, Mexico, 7 or 8 years old and produced copious amount of seeds the last 3 years - cross pollinated with the same or other SLP varieties only.
On a side note, I might have some seeds for trade so don't hesitate to contact me in private if interested.
