Melocactus - Melon Cactus, Turk's Cap Cactus
DESCRIPTION:This group consists of about 40 cacti from the West Indies, Mexico, and northern South America. These slow-growing cacti can be difficult to grow, but are fascinating. They are endangered in the wild. These globular plants produce a colorful cephalium, or densely spined crown, which gives them their common names of Turk's Cap Cacti or Melon Cacti. The cephalium is produced once the plant reaches maturity, at which time the plant quits growing. The areoles at the crown of the plant modify to form a large amount of wool and bristles. This cephalium can grow for many years. From the cephalium, pretty flowers and fruits are borne. M. concinnus has a bluish-green or green stem about 4 inches high. The 10 to 13 tuberculate ribs are covered with downy areoles. The reddish-colored spines eventually turn gray tipped with brown. The cephalium only grows about an inch high and up to 23/4 inches wide. The youngest part is covered with thick, white wool suffused with red bristles, while the older parts are mostly covered with the red bristles. The crimson flowers are followed by red or pinkish-violet fruits. M. matanzanus is a pretty, globular-shaped variety that reaches a height of 5 inches. This light green species forms a cephalium when about 6 years old and 3 inches in diameter. The cephalium is covered with rusty-red spines. Dark pink to scarlet flowers are produced and are followed by large, pink seedpods. This plant flourishes in sun or shade. M. salvadorensis varies greatly, but ordinarily has a green hemispherical body covered in reddish spines. Its red-orange cephalium is produced when it is about 7 years old. In the summer, pink to cerise flowers are borne; they are followed by large, red seedpods.
POTTING: Melocactus are tricky to grow, but given the proper care, will produce interesting and attractive specimens. Melocactus need a minimum temperature of 60º F. They have shallow, wide-spreading roots; therefore, grow them in pans or other wide, shallow containers that have excellent drainage as these cacti are rot prone. They should be grown in a very porous, rich soil that doesn't ever build up deposits of alkaline. In the summer, strong sun is beneficial as is frequent but light feedings. Melocacti shouldn't be given too long a winter rest. Some water in the winter is necessary. Repot in the spring if their roots become cramped. Generally, they should be repotted every other year in order to provide fresh soil. However, this doesn't necessarily mean they'll need larger containers. Fill about a quarter of the container with broken crocks, gravel, etc. to promote good drainage. Firm the potting soil. After repotting, do not water for a week or more.
PROPAGATION: Seeds may be sown in containers filled with a general-purpose cactus and succulent potting mix. Sprinkle the seeds evenly over the surface of the compost. Cover the seeds lightly with some grit, moisten the container and place in an area with high humidity and warmth. Transplant the seedlings when they are large enough to handle. Waiting too long until they are overcrowded can cause rot. Gently separate them so as not to damage the delicate roots. Transplanting will be easier if the soil is slightly moist. Seedlings can be potted singly or with several to a pot. They seem to do better with a few together rather than by themselves.
VARIETIES: M. bahiensis; M. intortus; M. matanzanus; M. communis; M. neryi; M. oaxacensis; M. concinnus; M. guaricensis; M. salvadorensis; M. azureus; M. belavistensis.
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