Root problems with Pleurothallids - Orchid Board

Flowers · #1 10-10-2007, 07:59 PM

I've been growing Pleurothallids in a large terrarium for almost a year. They're alive and flowering, but have all but stopped producing new growths, and when they do, the new growths don't put out roots, and die. All new roots that start to grow die back shortly after starting or after making contact with their mounts. Other than air circulation, what could be the problem?

Ross · #2 10-10-2007, 08:05 PM

I only have one (Pleurothallis tribuloides) and don't have a problem. Here is my regime: A fan runs 24/7 across all my mounts, including this one. I dunk the orchid every other day in weak fertilizer mix (125ppm Nitrogen MSU mix in RO water). Other than that I enjoy the blossoms. It has produced large new growths with accompanying blossoms. New roots with nice red tips are occurring every day. So maybe air circulation? Humidity runs over 90% 24 hours but fan runs all the time.

Flowers · #3 10-10-2007, 08:43 PM

How do you keep the humidity so high with the fans?
Are the fans blowing directly at the mounts?

shakkai · #4 10-11-2007, 03:51 AM

Flowers, what are they mounted on? Are they mounted directly or is there a sphag cushion? What kind of water are you using? When the roots die back, do they dry and shrivel or do they just turn brown and mushy?

Ross · #5 10-11-2007, 09:55 AM

Quote:

Originally Posted by Flowers

How do you keep the humidity so high with the fans?
Are the fans blowing directly at the mounts?

The Pleurothallis tribuloides is right in the center with the red flowers (hanging). The misters run 3-4 times a day for 5 seconds and one fan is totally inside running 24/7 blowing from left to right across the mounts and roots. In addition there is a second fan mounted thru-wall at upper right. It runs only at night for several hours for air exchange.

Flowers · #6 10-11-2007, 02:53 PM

Quote:

Originally Posted by shakkai

Flowers, what are they mounted on? Are they mounted directly or is there a sphag cushion? What kind of water are you using? When the roots die back, do they dry and shrivel or do they just turn brown and mushy?

They are mounted on tree fern with sphagnum. I'm using store bought purified water (it's bad, but better than tap). I'm buying an RO unit sooner than later.
New roots dry and turn brown, if they grow at all, and old ones seem to melt away, if they grow at all. I have a M. caesia that hasn't put out new roots since I've had it, and the new growths it has put out are minuscule.

rsfrid, I have quite a bit more air moving around than you do in your tank. I'm wondering if it's a water issue.

Ross · #7 10-11-2007, 03:49 PM

Quote:

Originally Posted by Flowers

rsfrid, I have quite a bit more air moving around than you do in your tank. I'm wondering if it's a water issue.

Maybe. I am pretty sure they like really high humidity, also. I use RO water with MSU mix at every dunking (every-other-day or so) and RO water several times a day flushes them via the misting system. So you may be right. "Purified" water at grocery stores is glorified tap water (usually) and maybe that's the culprit?

I'm guessing, though, that humidity levels may still be lower in your situation than the plants desire. My plant grows really long roots, nice bright red tipped, and seems to keep all of them. Sending up new red buds now.

Flowers · #8 10-11-2007, 04:05 PM

I guess I'll have to throw a mister in there too.

shakkai · #9 10-11-2007, 04:36 PM

Yes, my guess is the humidity. Most Pleuros like to be on the damp side, and with it being mounted, I'm betting it dries out to quickly. If humidity isn't high, the plant will be losing quite a lot of water through its leaves and literally sucking the roots dry.

I use tap water when I run out of rain water, and so far there has no adverse effects. Though I have heard from many that there are some Pleuros that are extremely sensitive to water quality.

The first thing that I would address, though, is the humidity around the plants.

jmateosky · #10 10-17-2007, 10:44 AM

Folks,

These plants grow on moss covered trees, where there is always a nice breeze. and always moist. The moss is faily loose. It holds moisture but there is plenty of air in the moss. For me it sounds like a lack of air movment. I have seen many plants die where people TIGHTLY pack spagh. moss around the roots. the looser the better!