Yellowing leaves on beallara's new growth

[krienschmidt]

I got this beallara orchid last winter, and at the time I noticed it's leaves were darker than my other beallara and oncidiums but it was in bloom and looked healthy otherwise. Since then I have several new growths coming in, all about 5 or 6 inches tall now but ALL the new growth leaves are coming in much lighter and in fact turning yellow. I have totally lost one of the leaves which is worries me. I have treated it several times with physan 20 and put it up with my phals where it doesn't get as much light. I try and go easy on fertilizer, no browning, just yellow and I water it about 3 times a week. Any other ideas or suggestions out there. As always thank you for your time and help.


http://www.orchidboard.com/community...laraleaves.jpg

[SaraJean]

Is the new growth still actively growing? If it's not drying up or if you don't see any signs of rot at the base of the the new growth, the different color could just be a response to it growing in more light than it used to. My beallara and miltassia did something similar to this (hard to tell with the pics though) when I changed their lighting. Old leaves stayed a bit dark and new leaves came out more chartreuse. As long as everything else looks good: roots, media, pbulbs.. you should be ok

Edit: how much Physan are you using and how are you using it? That could do more harm than good. If you don't know what is going on with your orchid, don't just blast it with chemicals which could turn out to be totally unnecessary

---------- Post added at 08:00 PM ---------- Previous post was at 07:43 PM ----------

Could also just be a case of overwatering, did you pot it in the same mix as your other beallara?

[estación seca]

That looks to me like spider mite damage. Thin-leaved orchids are very susceptible to spider mites. Look for fine silvery cobwebbing on leaf undersurfaces. Or, wipe a paper towel lengthwise under the leaf and look for brown or red streaks.

If you have those, immediately carry the plant to the shower or sink and use a strong spray of water on the undersurfaces of all the leaves. That will rinse the adults off the plant. Look up spider mites here on Orchid Board for further suggestions. I use 70% isopropyl alcohol.

[krienschmidt]

Sara Jean, I repotted it in re-pot times oncidium mix, it was in sphagnum moss when I got it March. My other beallara is potted in a small bark and coconut husk mix, and now that you mention it the one in the small bark and husk is doing fine. The new growth is still growing but the bottoms have more brown than I'd like to see. Maybe cut back on watering, watch it. If I have to I'll take it out to look at the roots and put it in a different potting media. I have not seen any signs of spider mites, I'm pretty cautious when it comes to nasty bugs. Ive sprayed it maybe 2 or 3 times in the past 3 months with the physan 20 solution. Didn't seem to hurt it but did not help either. Thanks for the suggestions everyone. Now I'm really thinking a potting mix and water issue?????

[bethmarie]

I'm inclined to agree with Estacion, from what I can see. You'll want to check for mites as he suggested asap, to avoid the scourge of their spreading to other plants.

[SaraJean]

Those mites can be quite hard to see. I did receive a plant with them once and needed a magnifying glass to spot them, maybe my eyes are just bad . The spray of water and wipe down with alcohol that Estacion mentioned, cleared them up. You just need to go back and repeat this treatment once a week to take care of any eggs that hatch

[Roberta]

Physan doesn't do anything for bugs of any sort unless it drowns them (soapy water is at least as good if not better for that) . It is good for algae and some fungal issues. For insects (mealy bugs, scale, thrips, etc.) an imidacloprid preparation (such as Bayer's 3-in-1) is systemic and also kills on contact. It supposedly contains a miticide as well, though for a serious spider mite infestation something more specific would probably be better. But don't choose your treatment until you know what you are treating!