Dendrobium - few unrotted roots - what can I do to save it?
 

Hi everyone,

I have been a frequent guest of this site, but this is my first direct posting - perhaps someone can give me some advice!!

I bought a dendrobium (I am sorry, I am not sure what kind it is) from a grocery store on sale. It still had some beautiful flowers when I bought it, but all of the leaves had blacks spots (some kind of fungus I guess). I took it home, re-potted it (probably into a pot too large for it), and washed the leaves with ethanol. It stayed in bloom for some time, but the leaves began to yellow and eventually they all fell off. I also perhaps made the mistake of cutting off the flower spikes after they had finished blooming..

It is winter here, so I thought that perhaps the leaves falling off indicated it could be a deciduous dendrobium. But the canes started to really shrivel and turn yellow. It looks bad.

The only hope i have is the little guy that is starting to grow. There are some tiny roots growing from him. Right now I have it in a western exposure that doesn't really get direct light - perhaps it needs even more light?

So I re-potted it again last night after removing almost all the roots, as they had become completely rotted. I took some pictures of it after I watered it - the medium is not usually that drenched. I was just wondering if any of you amazing orchid-growers had some advice for me.

Thanks so much!!
janie

Dendrobiums are very hard to kill and I think you can (easily) safe this one. I think you have here a warm growing Dendrobium, no rest required and that it lost it's leafs because it lost the roots due to overwatering.
I had a plant like this a year ago. No roots left on the mature canes and only 1 leaf left. These canes won't grow new roots but the new growth will.
Pot it in the smallest pot possible, if you have a smaller pot than this one, use a smaller pot. Place the older canes towards the rim of the pot and the new growth towards the center.
You even don't have to fill the entire pot with potting medium if you can't find a smaller pot, just a hint ;-)
For the new roots that emerge from the new growth it's important the plant doesn't wiggle in it's pot. I melted 4 holes in the side of the pot, placed a wooden stalk next to the side of the pot and attached it to the pot with cable ties. Then I attached an old cane to the stalk. That way the plant won't wiggle in the pot and the new roots can find it's way into the medium without getting damaged (due to wiggling).

About watering. I only sprayed the new roots once or twice a day, even when they grew in the potting medium. Make sure that the medium can dry every now and then and that the medium is airy.

For light, I would give an East facing windowsill for now... maybe South (don't know if the sun in Switzerland is stronger than in NL)

Nicole

I agree with Nicole, you have a good chance of saving this.

The new growth is a very good sign. As Nicole said you should get new root growth from that very soon even though the old canes will not grow any new roots. Hopefully the nutrients stored in the old canes will be able to support the young growth long enough for it to get established.

I agree about getting the smallest pot possible allthough with those tall canes it is likely to overbalance. I've used pebbles in the bottom in the past. This can have two purposes, one is that it reduces the volume of medium in the pot so you don't need to use a smaller pot, the other is that it weights the bottom to stop it falling over.

Thank you both, Nicole and Rosie. I will repot it in a smaller pot this evening. Rosie - the pebbles in the bottom is a great idea - the plant IS a bit top-heavy! An thanks Nicole for the tip about stabilizing the canes - that is something I had not thought about!!

Thanks again both of you for your help!