Mottled leaves on Dendrobium - Orchid Board

dbvogt · #1 08-21-2011, 05:51 PM

This is a keiki from Red Emperor "Prince" I bought bare root at a show in February and potted the Keiki in June. The leaves have taken on a mottled appearance that the parent does not have. Any thoughts on what this could be - lack of some mineral, lack of light? There are no bugs and no sign of black spots. Note first photo.

As a change of pace, the second photo is of D. "Spring Dream" bought at the same time. There are 7 new shoots coming up. Isn't this unusual? It gets the same treatment as the other Dendrobiums.

calypsoB · #2 08-21-2011, 05:59 PM

I will start by saying I am by no means an expert but you leaves kinda have the same colour that my catt got before I realized that a mite was munching away at it (well many). I didn't see any for a couple of months then boom! bug explosion. BUT like I said I am not expert and I do not know how to really diagnose problems

glengary54 · #3 08-21-2011, 06:25 PM

I agree with calypsoB, it looks like spider mite damage, check the backs of the leaves to see if there are any fine spider webs and or a black sooty substance, if so it is spider mites which thrive in hot, dry conditions.

As to all the new growths on your second plant which is a nobile type Dedrobium, it is quite normal for them to put out lots of keikis, it usually isan indication that the plant was watered to much during it's required winter rest period. The good thing is, more growths mean more flowers next year.

dbvogt · #4 08-22-2011, 03:35 PM

Thank you both. Spider mites are probably the cause and yet the plant was very far from the other orchids where I did see some webs on one plant and sprayed it right away.

On the rest period of the Nobile: the plant may have had its rest period before I got it bare root and I figured it was time to wake it up (late February in Florida).

I should start a new thread on this but wonder what will happen to those small shoots on the healthy plant in the rest period. I'm assuming all the leaves will fall off but will the shoots themselves dry up? Do growers purposefully omit the rest period for small plants just to get them to grow bigger in a shorter time?