Removing damaged leaves
 

Hi - I have a Dendrobium that I purchased in '97 for $10 at Home Depot - it has faithfully bloomed every year since and is just a little ol' lovely plant. Last summer we had extremely warm, humid weather (over 100 for a few days running). I had my orchids outside, in the shade, but obviously in the heat. I noticed that the Dendrobium started having white strangeness on the leaves later in the fall. I believe the spots may be related to the heat - don't know for sure. Anyway, this little thing proceeded to give me a spike with about 6 flowers on it around Christmas and 2 new healthy leaf growths. I am assuming with these events, that the plant is o.k. Question is - can I cut off the older leafs with the spots? They are really making the rest of the plant look terrible. If not, I guess I'll have to live with it but this has been such a good plant for so long and has always looked healthy - would appreciate any thoughts. Thanks very much.

I don't hesitate to remove leaves that detract from the plant's appearance so long as I am not giving the plant a "crew cut".

Same, if it's only 1 or 2 leaves, then I remove them. But if making the plant look 'nice' means removing a lot of leaves then I prefer to put up with the ugliness rather than possibly harm the plant by defoliating it! But i'll still remove the worst looking leaves to improve it somewhat.

Thanks for your input. Also, do you suppose that hot, humid weather contributed to this? As I said, I've had this plant for a long time and have never had the problem - also have never had such a hot, humid summer - sounds like it might be a link. Orchids are so beautiful - I don't have many but I do love them. Thanks again.

Most dendrobiums are deciduous. That is, after a year or two the canes lose all their leaves and become bare. This doesn't mean that the bare cane is useless. The cane not only supplies nourishment to the plant, bare canes can also bloom again.

Sunburn appears when the leaf can not cool itself. This can be related with high humidity because this makes it more different for the plant to evaporate water which is the cooling mechanism of the plant.

Also to high radiation, to high temperature and lack of water can cause sunburn or any combination of them can cause sunburn.

I'm with Rob on this one. The white appearance is common with sunburn. With the sun changing angles through the year, and me pruning the shading bushes sporadically, I had a couple of plants sunburned this past summer. Didn't think conditions were all that different, but direct sun on a phal or some dendrobiums can quickly cause sunburn. After it happened I watched periodically through the day, and sure enough, the sun peaked through the bushes for over an hour and hit the affected plants. A little earlier or a little later and it was fine.

As far as trimming goes, if it bothers me, I cut it. If I can live with it, I leave it.