Mammillaria longiflora stampferi
(This plant comes in a 3.5 inch pot. All of our plants are grown under the same conditions, although not all the plants are the same. You will receive a similar plant in size and shape to the ones in the pictures. Our plants are hand-picked and carefully selected to bring you the best quality possible. Please allow us up to 3 business days to process your order. If you wish to receive your order on a specific date, or have special instructions, please add a note at the checkout . The plant is shipped in its pot to prevent any damage to the roots).
It is one of the more difficult species to grow long enough to produce clumps, but if grown correctly, it will reward the grower with generous displays of purple flowers; plants should be allowed to become crowded in their pot. Keep in shallow and smaller pot than normal. Must have very well draining potting soil.
Watering Needs: Need regular water but do not water again until dry as it is specially sensitive to over watering. Also, it is a species that is dormant in the winter and require very little water (maybe even none) during the cold months.
Frost Tolerance: Somewhat frost tolerant. Light frost protection required. Minimum of 5ºC for safe growing (but hardy up to -5°C or less.)
Sun Exposure: High levels of light are needed to flower and for good spine development. Can be sunburned if moved from shade/greenhouse into full sun too quickly. During the spring it may be able to take full sun until the heat arrives at the end of spring. In an area that has hot afternoon sun, it may be able to take full morning sun, but requires afternoon shade or afternoon light shade.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz