As classified by Rebecca Tyson Northern, there are 6 groupings that describe the differences in growing needs of Dendrobiums. I am paraphrasing to avoid copyright infringement.
Type I (deciduous, so-called nobile type) intermediate to warm in summer, cool to cold in winter, full winter rest. Examples: D. nobile, D. chrysanthum, D. wardianum.
Type II (deciduous) intermediate to warm all year, full winter rest. Examples: D. speciosum, D. aggregatum, D. findlayanum, D. heterocarpum, D. superbum (anosmum), D. parishii, D. pierardii.
Type III (persistent) intermediate to warm summer, cool in winter, no winter rest - simply reduce water. Examples: D. densiflorum, D. fimbriatum, D. thyrsiflorum, D. farmeri.
Type IV (persistent) cool all year. Short suspension of water early autumn. Examples: D. bellatulum, D. secundum.
Type V (persistent) Intermediate all year. No rest. Examples: D. antilope and hybrids of type V and type VI.
Type VI (persistent) warm growing all year. Restrict water twice during year. Examples: D. phalaenopsis, D. bigibbum, D. superbiens.
Now, I have little personal success with any, except type II, so I can't help with culture on the others (I kill them more often not not - or they just up and die
) but deciduous type II are said to be the easiest for in-house culture, if one follows their needs strictly. I've found this to be true for D. anosmum. Hope this helps others.
The Six Horticultural Groups of Dendrobium
Threaded Mode
