Light and temp are OK. Most important is to keep them dry from Thanksgiving to Valentine's day. Mist a little every 2 to 3 weeks to keep the bulbs from shriveling but no watering during that time. Once something happens in the spring resume water and fertilizer.

Nick

Nick.....

Thanks for getting back to me so quickly with some answers for my questions about growing these orchids. More questions:

Grow potted, or, mounted? If potted, in what kind of medium?

While going through the dry winter period, do they need to be kept cool also?

Thanks for the help.

Frank

There must be easier Dendrobiums to grow in Zone 7. Den. aggregatum/ jenkinsii has a reputation of being difficult......
Here is a pic. of a plant grown by a member of the local orchid society, note the shallow tray.
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I prefer mine mounted. Lots of light, cool temps and very little water is the mantra between Thanksgiving and Valentine.

Nick

Dend. aggregatum is not difficult but you are absolutely right not to shade this plant during the winter. Year round temps of 60-90F ( will tolerate 45 at night in winter and plenty of water in the summer, almost none in winter. - Ian.

Thanks for the information.

This is a plant that I would like to try growing. I like the winter treatment which amounts to letting it hang in my sunny, south-facing window, with nothing more than an occasional misting. The micro-climate near the glass feels pretty cool, so that should work, also. The worst that could happen....it dies. It would not be the first, or last plant that I kill.

Thanks again.

Frank

Question:

Pseudobulbs will shrivel up in the dryish winter, quiescent period ... correct? Will they rehydrate and plump back up when watering is increased with the commencement of the new growth cycle?

Frank

There is a lot of debate about the degree of dryness needed by the Dendrobiums that come from climates with dryish "winters". The ones i grow (not Den aggravation) get watered sparsely in a glasshouse and whatever rainfall happens in winter here out in the shadehouse . Winter is mostly sunny and dry but you never know when heavy rains are going to fall in an erratic climate.

Dendrobium aggravation is rarely seen on orchid society benchings here and maybe that degree of flowering difficulty is what prompted an AOC Judging panel to give that orchid pictured above a cultural award. A very poor photo that does not do justice to a magnificent feat of culture.