can not repot dendrobium nobile :(
 

Hi again,
Yesterday a dendrobium nobile followed me home from the grocery store. :) I decided to repot her to see what is going on with her roots, since they were hidden under a mix of sphagnum moss and bark. Well, all the roots came out as a very massive ball with almost cemented media. I tried to dig it off from here and there but it seems she has really lots of roots and all are tangled. Also I was interrupted by some roots during all my attempts. The roots which are outside seems fine but, do you have any idea how to untangle her roots without giving her harm?

Soak it in water and try again.

There is a balance here. On the one hand it would be better in a larger pot with the roots more open, on the other you don't want to do so much damage that you ruin the flowers and set the plant back.

QWhen you reach the point that you daren't go further, in your shoes I would just drop pot it, ie put it in a larger pot and fill round with fine bark to give an open airy place for roots to grow into.

I had a Catt come with the same problem. It's waht I did and the Catt is blooming nicely. Gradually the impenetrable ball of roots will die away and the ones in the more open space should take over.

Thank you very much Bil for the quick response. That is the exact same thing that I had to do. Since I had to tear open the cheap plastic pot, all I could do was have her sit in a slightly larger pot with some fresh barks poked in the empty spaces.

I agree, if the roots are doing so well in its current media, I would try and remove what you can, but not go overboard on disturbing it just to get it all out. As bil said, drop it into a slightly larger pot with some bark.
It looks like a nice plant.

Remember that Dendrobiums do not do well if 'overpotted'. In a case like this:

A. Since roots are doing well, put it back in same size pot for now. Wait till it is done blooming.

B. When it is time to tackle the plant, soak the root ball in water. Then, pluck at it from all sides, untill you get the old center cleared out. At that point, repot in the smallest possible pot that you can it into.

Dendrobiums do well in a granular mix. With their fine roots, the best choice is bark/charcoal/perlite in a size slightly larger than seedling mix.
Seedling . . . . . . . . . . . . . . . 3-6 mm
Dendrobium & Miltonionopsis 5-8 mm
Cattleya size . . . . . . . . . . . . 10-15 mm

You could grow them in seedling mix, but then you have to plan on repotting every year, instead of every other year.

I have been using seedling bark, coal and perlite and worked very well for my dend. nobile. If I use seedling orchiata bark, can it last for few year before repotting?

I have never used orchiata (no benefit to 10 year life if you plant to repot every 1-3 years), so I can't answer that.

Personally, I use a spaghnum/bark mix & clay pots for my Den nobile hybrids, and that lasts two years no problem.

Using the seedling mix, I find that it looks fine at 12 months, but it breaks down before 24 months.