Mammillaria compressa cv. Yokan Origin and Habitat: The origin of this nursery produced cultivar is unknown, it was previously known as “Mammillaria sp. forma mostruosa forma cristata”.
Description: This strange Mammillaria makes a nice and tangled cluster of fine crests. Brownish-green or purple in full sun exposure with fine soft white spines.
Remarks: Sometime “Yokan” revert to the type producing some normal shoots. Which are not monstrous at all! And also some classical green Mammillaria compressa forma cristata. But all this very different forms are the same plant! They are epigenetic variation not genetic mutant!
Cultivation and Propagation: It is a relatively rapid growing species. This is easily grown into clumps, but it does often have an irregular pattern of offsetting. Water regularly in summer, but do not over-water (rot prone). Use a pot with good drainage and a very porous potting media. Keep dry in winter. Feed with a high potassium fertilizer in summer. It is quite frost resistant if kept dry, hardy as low as -5° C. Outside full sun or afternoon shade, inside it needs bright light, and some direct sun.
Easily clustering and easily flowered. Most plants will offset readily, and clumps can be produced in a few years.
Propagation:: By division of larger clumps or graft.
Exposition: Outside bright sun, filtered sunlight or afternoon shade, inside it needs bright light, and some direct sun. Subject to sunburn if exposed to direct sun for too long. Tends to bronze in strong light, which encourages flowering and heavy spine production.
Uses: It is an excellent plant for container growing. It always looks good and stays small. It look fine in a cold greenhouse and frame.
Traditional uses: The white, hooked spines of this spherical cactus were used as fish hooks in its native Mexico.
Pests & diseases: It may be attractive to a variety of insects, but plants in good condition should be nearly pest-free, particularly if they are grown in a mineral potting-mix, with good exposure and ventilation. Nonetheless, there are several pests to watch for:
– Red spiders: Sensitive to red spider mite. Overhead watering is helpful in controlling mites.