Leaf loss on Dendrobium Burana Sundae

Leaf loss on Dendrobium Burana Sundae

     Two months ago, my Dendrobium Burana Sundae arrived as a deceptive mess. It had many thick, tall canes promising a vigorous and fast growing plant, but the roots were a broken, rotten mess.  I ended up trimming most of them away, which is why I needed to add a stake to the pot just so the canes wouldn't topple over.

     In the past two months, the orchid has shed all of the leaves from its older two canes.  Since the dendrobium arrived with 3 generations of canes bearing leaves, I highly doubt that this is normal for this hybrid. Some dens are deciduous and regularly shed their leaves in the winter season as part of their growth cycle, but I don't think this is one such.

     In addition, all the older canes have developed shriveling, and the oldest cane has taken on a ghastly orange-yellow color. I have no way of seeing what's going on with the roots right now (I don't want to disturb the plant yet), but I suspect that the rest of the old roots have died off in the last two months.  It's likely that only the cluster of newish 2-3" long roots from the newest cane remain.  I'll probably check up on them in a few more months.

     In the meantime, the orchid lives in my terrarium, where it's hopefully benefiting from raised humidity.  I water it whenever the humidity tray on the bottom of the pot dries out, which is about every 2 weeks.  I've also been giving it followup treatments with systemic fungicide, because its roots were in such a damaged state, and because I am generally so suspicious about the orchid's health.

     The orchid is currently planted in "dendrobium" mix from rePotme.com, but I'm wondering if maybe I should move it to coarser bark to help it dry faster.  Regardless, I won't be changing anything until after I return from the holidays.

New orchid: Dendrobium Burana Sundae

Dendrobium Burana Sundae

     I had temporarily given up on dendrobium orchids after my two failed attempts at growing Den. victoria reginae. I think the problem with that species is that it was a cool-grower, and my apartment got too hot for it in the summer. However, I still really like how dendrobium canes look, and I've been meaning to try again with a den hybrid (which I hope to be more forgiving about its culture needs).

     A few weeks ago, user 'Leisurely' posted some beautiful photos of his dark dendrobium blooms, and I was off searching the internet for vendors selling one of these gorgeous plants.

Dendrobium Burana Sundae (Photos courtesy of 'Leisurely'): Original link

     

     I am now a proud owner of Den. Burana Sundae.  The orchid I received is larger than I had been expecting; this is certainly no miniature.  The dendrobium has 6 canes, the largest of which is 18 inches tall.  Three of the canes have leaves on them, while the other 3 are leafless.  The leaves are thick, sturdy, and 5 inches long.  One of the canes has the remnants of an old spike at its tip, so I know this orchid is big enough to bloom.

Dendrobium roots, before and after trimming

     The root health of the dendrobium is questionable.  Most of the orchid's roots (even the ones that looked greenish) were either rotten, or badly broken in many places with the velamen peeling off.  I ended up trimming off about 2/3 of the root mass.

     The orchid had a handfull of new roots (thick and white above) growing off from the newest cane, but they are actually less reassuring than they could have been.  About half their root tips are blackened and no longer growing, an appearance that reminds me of the root problems on my Oncostele Pacific Perspective.

Stubby blackened new roots tips on Oncostele Pacific Perspective (May 2012)

     Since I ended up writing off my oncidium root problems as potentially fungal in origin, I made sure to give both the new dendrobium (and the Aliceara Matthias) a good long soak in systemic fungicide before repotting.  

     Ultimately I don't know how much of a root system a dendrobium of this size needs to grow healthy.  I'm hoping that the fungicide treatment will stave off any infections that might have been present, and that good care will take care of the rest.  The dendrobium is quite top-heavy, so I potted it into a 4" ceramic pot for balance, and added a stake to support the canes.  I used 'dendrobium' orchid mix from Repotme.com.

     It's now been 1 week since I've repotted the dendrobium, and it looks like it's shedding the bottom two leaves on one of its canes.  I hope that's just the stress of shipping+repotting and nothing more sinister.