O. sphacelatum is an epiphytic species which grows well on bark in cultivation, when extra feed can be given during the growing season to enable the plant to produce large pseudobulbs. ‘The aerial roots will live for several years, often until their pscudobulb becomes leafless.
C. devonianum has dimunitive pseudobulbs and requires these thick roots to ensure a ready supply of moisture, although not all small-bulbed orchids possess thick roots. Within another twelve or eighteen months this root ball will be solid and the plant ready for ‘dropping on’ into a larger pot.
Paphiopedilums make a meagre root system, but the few roots that are produced from each growth grow continuously passing on a steady supply of nutrients to the plant, which otherwise have little means of moisture storage. Without pseudobulbs the roots become even more important to the plant, and if they die prematurely the plant will suffer from starvation and dehydration. -Therefore underwatering is the great enemy of paphiopedilums.
Paphiopedilums growing in their natural environment produce roots that extend for many feet across the surface of a rock face, taking advantage of any crevices or burrowing into surface mosses or forest litter. In this way they obtain sufficient moisture without the danger of becoming too wet.
An explosion of new roots erupts from the base of the new growth, but only after the latter is fairly well developed. New roots always follow new growth. It would have greatly benefited this plant had it been repotted before the growth of new roots, which have now developed as aerial roots. The roots if terrestrial would have found more food in the fresh bark than they can do as aerial roots.
To repot this plant now would virtually destroy the whole root system, as the roots would be buried in the compost, where they would suffocate and die. Therefore this plant is best left for the season, its aerial roots fed, until the next resting period commences. Repotting can be done at the right time in the spring after the commencement of the next new growth, before any new roots appear. The existing aerial roots can then be trimmed back to within a couple of inches (5 cm).
