repotting finely rooted orchids

[siriusmk]

Hello everyone,

I'm sure there are probably many posts on this topic, but here goes another one. I have successfully repotted many phalaenopsis orchids and assumed the same principles would apply to repotting my miltassia charles m fitch Izumi, except I'm not used to seeing roots that are so fine. I first soaked the old pot with some water and a drop of superthrive before taking it out of the pot. When I took the plant out of the potting medium, 95% of the roots were medium brown and it was hard to tell if it was root rot or healthy because they didn't feel quite mushy and there was a huge clump of what looked like brown florist foam (it's usually green) in the center of the roots. I managed to get most of it out and washed the roots off, and it was a little bit lighter, but not by much. I trimmed 70's of the brownish roots off, but left some on for fear i was doing the wrong thing. I can tell that two of the young pseudobulbs are putting out whitish green roots and there are a couple of healthy whitish green aerial roots that still exist. I guess my question what do healthy roots look like in orchids with a fine root system? Are they supposed to be white when wet? or green? or both? I ended up using fine coconut husk, large perlite, and fine pieces of charcoal to repot my miltassia. I hope it survives this very traumatic experience.

[kmarch]

Dear siriusmk,

I am not an expert on Milltassias but have grown Oncidiums, Odonticidiums, and a few others in the same alliance. My (limited) experience wiht these types is that healthy roots are cream-white and crisp even if small. Deep in the mix they'll be cream-white and dirty but still crisp. If mis is firmly sticking to a root I do not like to remove the piece of mix because I invariably damage the root. Besides I don't think a few pieces of old mix going in with new will do much damage. Rotted roots or dead roots are dark brown or greay or black and are mushy and will give way if gently tugged. Fresh roots don't to this. Tug gently though on thin-rooted plants.

I find roots exposed to air above the mix will get a white, shiny sheen and will often turn green when watered. I find this true for many epiphites. When the roots begin to dry out they'll turn back white. The white, shiny, vellum-like (sp?) layer is a kind of spongy outer layer of root that soaks up water. Like a sheet of paper it gets translucent when wet and the green tissue beneath it can be seen.

One thing I have noticed about the few Oncidium aliance plants I have grown is that new roots literally explode from the bottoms of new growths. Given this tendency for eager root growth I do not believe your plant is in danger. it is probably worse to leave rotting roots on.

cheers

[siriusmk]

Thank you for your input. It was very helpful since I wasn't quite sure. I have posted some pictures of what it looked like after I trimmed off about 70% of the roots . I wonder if most of them were dead is because of that 1X1 block of florist foam that was embedded at the base of the pseudobulbs so all the roots coming out of the middle pseudobulbs were engangled in that drenching wet florist foam. I am upset to have made that discovery especially since i purchased this orchid from a reputable orchid dealer.

[Lucinda Brown]

Hi, sounds to me like you did the right thing,also.The 'florist foam' was most likely was left from when the orchid was planted as a baby,they're called plugs-a tiny plant rooted in a piece of foam. This is how many growers receive stock.In what they call 'plug trays'.The little seedlings are popped out of the 'plug trays' where they're only rooted in this foam and put in larger pots,foam and all,when they are ready for transplant.Good luck!I'd maybe cut my watering back a bit if you found that many rotten roots.

[kmarch]

Yes, the florists foam thing is very stranve. I'd never heard of that happening. Sometimes odd things like this can get in under the radar of even reputable vendors. Unless a vendor grows their own seedlings or receives everything bare root, it can happen. For this reason, I'm usually not shy about poking around in the mix of a plant I decide to buy.

It looks like you have some nice actively growing roots in that root-ball so I think you'll probably be ok. It looks like the pseudobulbs might be slightly dry, but until the new roots get grown the plant will only be able to take in so much and so it will use its pseudobulb reserves until then.

Keep us posted on your progress and post some pics when it blooms. As you've probably noticed, we love the pics here at orchidgeeks.

cheers

[Aniko]

I think everything will be fine, since you've chosen the right time for re potting - when the new growth starts rooting.The new roots hopefully will replace the lost part of the root system.

[siriusmk]

I still have not chopped off all those brown roots. I know this may sound like a stupid question, but should I?

[Aniko]

Well, if you can not make the difference between dead and alive, preferably just re pot.
Try and find out the difference:
If touched and squeezed, the dead roots fell apart: a kind of hollow tube can be pulled off from a thin, wire like stuff.
A healthy root is firm, crispy and not hollow, has a whitish color inside...
Good luck!

[slippery_biscuit]

I'm sort of tagging onto this thread, but it seems applicable. I had repotted an oncidium (Star Wars x Golden Shower) a month or so ago into a medium bark. Since then I've learned a bit about finer roots vs the more stout ones and thought to put it into a different mix. Root growth seems good, lots of white and green ones coming out. The thing is these new roots are, for the most part, growing up and out of the pot, just like the foliage. I don't think I want to bend them into the pot for fear of breaking them. The plant is 4"-6" tall; I'm thinking of putting it into a small basket with a little coconut fiber and growing it like a Vanda. Sorta. I've previously cleaned up the dead roots. Interesting to observe that some of the ones I left 'cause I wasn't sure (and they still look a little brownish and shriveled) have new root growth out on the ends.

Comments??

Happy Easter!
Jeff

[Ellen]

Fine-rooted orchids like oncidiums do best when potted in a medium like fine bark or sphag. Brown roots may not be dead, just discolored from the bark medium. I wouldn't cut off anything that isn't obviously dead. As Aniko says, your plant should be fine since you're repotting it during a period on new growth. The main roots that are important are the ones on the new pseudobulbs, anyway.

[Aniko]

["I'm thinking of putting it into a small basket with a little coconut fiber and growing it like a Vanda. "]

Jeff - I think this experiment could have good results if you are able to keep the roots wet enough - it depends a lot on your environment.
I can see that mine are doing excellent in sphagnum moss or small bark topped with sphag. Earlier I almost killed my Miltassia because I kept her too dry...

[slippery_biscuit]

I looked again at the plant and with Aniko's comments in mind, I'm going to take some coconut husk and pull it so as to "fluff" it up, then mix in some sphag, if you can call it a mix. The moss ought to help hold in moisture and the husk will keep it quite airy. I mist/water my mounted plants daily, so what the heck, it's just one more.

Aniko, I snatched a Miltonia off the salvage rack a couple of weeks ago. Nothing wrong with it, just ending its bloom. Did some reading and seems like they like light, temp mid to cooler, and I read to put them in a well draining mix, but they like water and not to let them completely dry out between waterings. Does that sound about right?

Will advise in a few months on the Oncidium Experiment.

J

[Aniko]

Unfortunately I have no personal experience concerning Miltonia.I have only Oncidium, Miltassia and Degarmoara.This general information sounds right and I think we always have to find by practice our particular adaptation of the "general rule", adjusted to our particular growing conditions.
But maybe somebody else will share its personal experience .

[fred]

Aniko I have just found a few links you may find useful.

http://www.alohaorchid.com/MiltoniaCare.aspx

http://members.lycos.co.uk/raybilton/orchidcare.htm

http://www.brennansorchids.com/milt.html

http://www.1888orchids.com/text/orch....miltonia.html

[Aniko]

Thanks, nice of you. As I said, I have no Miltonia yet, but I really like it; at the next opportunity I'm going to buy one...

[jerrymeola]

Miltonia and all thin rooted Oncidium alliance orchids never seem to have enough roots to survive but do very well with what they have.

What you thought was florist sponge in the pot is a seedling culture that enables the young plant to keep moist enough to grow. Without it a young plant is very hard to keep. Everyone should realize that with young seedlings (all types) it is important to keep them moist all the time. Much more than you would do for an adult plant.

The roots were probably fine. Root rot is not that common on Oncidium. Bulbs soften and rot first. Many Oncidium grow up and the roots of new growths remains out of the pot. I prefer to mount mine on wood so they grow up naturally. I let all exposed roots stay that way.

With Miltonia you need to remember they like cool temperatures (hard to keep in Florida) and like all Oncidium Alliance they benefit from constant air circulation.