Ariocarpus retusus / 10 seeds (False Peyote, Star Rock, Living Rock)

Ariocarpus retusus is a cactus species native to Mexico and highly sought after because of its unique structure of star-shaped rosette formed by fat, triangular tubercles and lovely flowers.

Ariocarpus is a genus in the Cactaceae family known for slow growth rate, but Ariocarpus retusus is the fastest growing species in this genus. It’s also one of the most easily cultivated species in the genus. It occurs in high Chihuahuan desert at elevations between 1300 and 2000 meters on calcareous hillsides and infrequently gypsum plains. Its tubercles protrude slightly above the ground, while the flat tuberous body is below ground.

Stem is blue-green, globose, rounded on top, flattened, 3-12 cm tall and 10-25 cm in diameter. The leaf-like tubercles are divergent, erect, basally compressed, usually becoming attenuate at the apices, convex or 1-3.5 cm wide, almost as wide as long. At the tips of the tubercles, there are areoles that are rounded and 1 to 5mm in diameter.

In October, Ariocarpus retusus produces white, green or rarely pinkish flowers that are 10-25 mm long and 3-10 mm in diameter occasionally with reddish midribs. Blooming and pollination can occur very quickly, so you can enjoy the annual show! Seed pods are white, green or rarely pinkish, 10-25 mm long, 3-10 mm in diameter. They normally swell and mature within the safe environment of the tubercles and wool, and expel without a warning 6 months to a year after the bloom. The charm of Ariocarpus retusus lies also in the fact that it’s an extremely variable species with its tubercle size and shape varying widely. Sometimes a terminal areole is present at the tip. This vast amount of phenotypic variation has given rise to several variants. All the Ariocarpus seedlings are spiny and pretty different than adult specimens, although the spines are feather-like.

Ariocarpus retusus needs full sun to light shade and a well-drained, non-organic soil compost. This easy-growing cactus survives winter and thrives in spring and summer for years to come.  Due to the large taproot and succulent tubercles, this cactus gets the huge advantage of longevity and water storage. It also has the capability of shrink or recess into the ground during severe droughts, and thus reducing surface area exposed to the sun. This also highly contributes to its survival. Ariocarpus retusus can take plenty of sun. However, if you buy a plant grown indoors, don’t keep it immediately in full sun. instead, slowly introduce it to more and more light. Also, avoid any ariocarpus in the rain as it can quickly die.

Ariocarpus retusus likes the warmer weather, but is typically hardy to below freezing temperatures for a short time. It also doesn’t seem to show negative response to humidity. But it’s advisable to keep it in low light during severe summer.

Ariocarpus retusus needs ample water during the growing season. You can use a weak, low-nitrogen fertilizer during this season to encourage growth.

Ariocarpus retusus is typically pest-free, but be watchful for mealy bugs in the more vulnerable areas of the tubercles near the main stem. Root rot is the main threat faced by Ariocarpus retusus. So, the plant should be kept dry whenever there are chances of cold. Watering from the bottom is beneficial to the appearance of Ariocarpus retusus as it keeps the ‘wool’ on the plant’s top from becoming matted or discolored. Overwatering should be strictly avoided. Even a little bit of water is enough for this plant for a long time. While watering in spring and summer, you should do so very lightly. You should choose a fertilizer which is very weak and contains calcium. Watering should be stopped totally in the winter, unless tubercles are so shriveled that they lose dimensions.

The container chosen for Ariocarpus retusus should be deep enough to accommodate the large taproot to grow comfortably, survive and thrive. While watering in the pot, try to water very small amounts around only the root zone.

Ariocarpus  retusus is perhaps the easiest species to cultivate from seeds. However, the plant usually takes 6 to 10 years to reach flowering size, so, it’s occasionally grafted.