
Many very exotic, unusual succulents are outstanding garden plants, but are very difficult to find commercially. Reasons for them becoming rare succulents include their sometimes being hard to grow in the first place, or they may be difficult to propagate because they produce few offsets, don’t root easily, or fail to produce seeds.
Until the fairly recent advents of tissue culture propagation and access to far-away sources over the Internet, many were available except from very small rare plant nurseries and one-on-one sharing between gardeners or members of specialty plant organizations.
Many other exotic succulents are easy-to-grow, easy-to-propagate plants with unusual twists, such as the spineless prickly pear cactus (Opuntia cacanapa ‘Ellisisana’) and the various “mother of thousands” and “alligator plants” (Byrophyllum) which grow entire new plants on the tips of leaves. Cold-hardy Jovibarba are closely related to and look like common hens and chicks Sempervivum, but don’t form chicks; their crowns split into several, and have to be divided, which is not as easy to do on a commercial scale.
Because these interesting plants are not widely available in garden centers, “garden variety” gardeners don’t come across them in the first place.
Oddities
Any list of unusual or difficult-to-find succulents will be bound to neglect some of the most bizarre. And many real gems may be common as sand to gardeners in mild climates where they are widely sold and grown. But to folks just getting into succulents who want something a little different from same old, same old, here are a few unique succulents worth seeking out – and sharing with others when you can.
Start with “night blooming cereus” plants (Epiphyllum, Hylocereus, and others) which often have ratty-looking foliage but are spectacular when their nighttime flowers unfurl – including those that go beyond the common white flowers and glow in bright hues of yellow, red, crimson, and orange. And in place of the old “string of pearls” Senecio, look for the “strings of banana” or “fishhook vine” (Senecio radicans), a cascading succulent with small banana-shape leaves that grow upwards, resembling a green string of fish hooks.
Of the many different kinds and sizes of Aloes, a few really stand out to collectors, including spiral aloe (Aloe polyphylla) with its rosettes of small leaves in tight spirals. Of the several with reddish foliage, sunset Aloe (Aloe dorotheae), when given plenty of sunlight, turns bright red with whitish spines.
Giant century plants (Agave) are very common, but tuxedo agave (Agave americana mediopicta ‘Alba’) has clean, broad white stripes; it is slow to make pups, so harder to come by. And the small, rapidly-spreading Tricolor Agave (Agave lophantha ‘Quadricolor’) is compact and cold-hardy (down to 10 degrees Fahrenheit), and will quickly fill a pot or raised bed; its stiff leaves are green with a paler green stripe down the center, and pale yellow leaf margins that partly turn rosy red in sunlight giving it a four-color effect.
Finally, everyone seems to grow some kind of Sansevieria. But for collectors getting bored with the wide, beaver-tail leaves of Sansevieria grandis and Sansevieria cylindrica’s thin, arching leaves that are round in cross section like a carrot root, there is Sansevieria kirkii ‘Coppertone’. It has very stiff 18-inch green leaves with uniformly wavy edges, metallic copper blotches that turn pinkish in bright light, and a thin red leaf margin. And its flowers grow in a roundish cluster on short stems rather than the long stems of other Sanseverias.
There are so many, many more great collectable succulent oddities on savvy gardeners’ wish lists!
SOURCE:http://www.diynetwork.com/how-to/outdoors/gardening/rare-and-unusual-succulents