They need a hard winter rest with cool temps and bright light. I grow my pierardii and my unicum the same.
This winter I put mine outside starting in late October and rarely watered it (this was rather hard for me as I tend to have an over watering problem). The temps got to around high 60's day to low 60's, high 50's night. The temp would even dip down to the low 50's high 40's some nights. It got plenty of sun. Around mid January I moved it into my terrarium where it got warmer temps, never going below 60 at night and the day temps now are high 70's.
I tried an experiement as well with my pierardii's. I have two, I hung one outside and I hung one in my terrarium all winter. The one in the terrarium didn't get as much light or low temps and is suffering for it. It has way less buds : /
I think the key to reblooming dendrobium pierardii's is 1. Winter rest. No water even if u feel sorry for it. Maybe a quick water once a week if it's mounted or u live in very dry climate. 2. Cold weather. Andys and many other vendors list this as a intermediate/ warm grower but mine need cold winters! 3. More sun in winter then in summer! As much sun as possible without leaf burn.
Very informative, thank you. I will try to follow this care for next fall and hopefully I will get some buds. They really do have beautiful flowers, if I can ever get it to. Post you bloom pictures!
So here's the latest with whats been happening with my Dendrobiums ( and others) in spike.
My Dendrobium Pierardii just bloomed today. So far no scent. The lip isn't as fuzzy as I've heard people describe; first spike appeared on 2/1/15. All 4 buds open on 3/14/15.
My Dendrobium unicum is still in bud but its growing like crazy. it has several buds and spikes and 2 new canes growing; first spike appeared 1/26/15. first bud still hasn't opened.
My Dendrobium micro-chip is still in bloom. I bought this one in December in bud and it is still blooming almost 4 months later. the first flowers started to fall about 2 weeks ago. My other dendrobium micro-chip that I've had for over a year is starting to spike as well. looks like i'll have almost a full year of that delicious micro-chip fragrance.
My Sedirea Japonica started to spike on 2/5/15. i started seeing buds forming on 3/10/15. I'm so excited about this one. the fragrance is suppose to be amazing.
The lights are working very well! I like them because they don't give off any heat. I ended up adding another 22 watt white,red, and blue light and Moved my terrarium closer to the window.