Help!am I loosing my whole orchid collection?Fungus?Bacterial? Rot?

[Paytyn2flex]

Hello, I'm not sure if I'm posting this in the correct way, so pls advise if that is the case. My issue is, I have all my orchids under a pergola (approximately 13ft x 34 feet)for the past 2 years. All Phalaenopsis are on the patio table. My Vandas hang together where the sprinklers can water the roots almost daily and I have 2 orchids (I think one is an oncidium, and 1 is a brassica) that where given as a gift).. then I have some dendrobium on shelves up top... I water the phalaenopsis maybe every 8 days, they are planted in orchid bark mix) The Vandas and oncidium and brassica get watered daily, and the dendrobium maybe every week. I dont know if I have a bacterial infection or fungus or the dreaded black rot. I have tried spraying with hydrogen peroxide. I'm going to try to attach pics. The phalaenopsis with the all yellow leaves actually had the top,new growth, leaf fall right out. Pls help!!
I live near Clearwater Florida
I did spray all with Physan 20 this morning. 1I just feel like I can't breath, thinking they are all going to die. Do I trim the spots and orchid leaves?

[MrHappyRotter]

The Phal looks like it's seen better days but the rest look reasonably healthy to me.

[estación seca]

I agree they mostly look OK. Do any of them have soft black areas? How cold has it been at night? Phals don't do well with cold nights. Vandas neither.

[Roberta]

Except for the Phal, I also don't see any issue. The phal is compost (it happens) but the others look fine. Don't panic about the occasional black spot. Not serious. and peroxide is pretty useless, don't bother (and at any rate keep it off the roots) Physan is a good fungicide. Won't resurrect the Phal, but won't hurt anything either

[Paytyn2flex]

Thanks for the replies! So the yellowing leaves, that aren't at the bottom, are ok? How about the spots on the vanda leaves? Or the black circles on the oncidium and brassica? It dropped to about 45° for maybe 3 nights, but then it goes back up to 65-70°.. should I cut the spots on the leaves with the black spots and dip with cinnamon? Mayne just throw away that one phal that clearly is a goner? How often should I spray Physan 20? And about how soon should I see improvement. What about the beautiful vanda that has the black spots in the middle.. the leaves are yellowing around it. Should I cut off dead roots and leaves and repot?

---------- Post added at 09:00 PM ---------- Previous post was at 08:56 PM ----------

Also what about the black spots on pic 9? Or the spots on pic #3,#4 and #6 of 9?

[Roberta]

Don't cut. Ignore the black spots. they are localized. Probably a bit of cold damage. You can get local fungal issues when cold water sits on a leaf. It doesn't go anywhere, maybe a little unaesthetic but no sign of danger. Brassias and other Oncidinae eventually shed old leaves naturally anyway. Cold can make a Vanda drop a fw lower leaves, just let it do what it wants to do. Looks like you have a keiki starting, too. So dump the totally yellow Phal, the rest of the plants will fine. Tht Phal did probably get outside its survival range, the others are more forgiving. For the record, I grow a lot of orchids outside (but not Phals) in an area a lot cooler than yours. Leaves may not win any beauty-contest prizes, but it's amazing how much cold these durable plants can tolerate. But don't cut unless you see rot spreading. Surgery is likely to do more harm than good.

You MAY actually find that you get particularly good blooming when the weather warms up... many orchids respond to a cold jolt by blooming. (The shock scares them into a desire to reproduce) Leaf damage will be there until the leaf is shed, but we grow orchids for the flowers not the leaves, yes??

[estación seca]

45 F / 8C is too cold for most hybrid Phals and Vandas. That would explain what happened to them. People try to keep Vandas above 50F / 10C and warmer than this is far better. A perfectly healthy and dry hybrid Phal will often survive those temperatures but not always.

Don't use fungicide sprays unless you know what fungus you have and you know it is susceptible to the agent you choose. Fungicides kill beneficial microorganisms, which are generally very important to plant health. Most plants are highly resistant to most fungi when growing conditions are good. The black spots you're seeing are likely caused by cold and not fungi.

Motes Orchids will send a monthly E-mail newsletter of what to do with your Vandas in Florida. You can sign up on their Web site. It is extracted from Martin Motes' book on growing Vandas in Florida, which I highly recommend. I find it useful here in Phoenix, though my climate is much different.

[Paytyn2flex]

Again, thank you all for the advice. I'll keep you updated with how they fair. Unfortunately, I think here in Florida, we're just getting into the cold weather, so I wonder what to do with them if gets colder? I could put them in garage, but they wouldn't see any sunlight. Any thoughts on that?

[Roberta]

Originally Posted by Paytyn2flex

Again, thank you all for the advice. I'll keep you updated with how they fair. Unfortunately, I think here in Florida, we're just getting into the cold weather, so I wonder what to do with them if gets colder? I could put them in garage, but they wouldn't see any sunlight. Any thoughts on that?

Bring the Phals inside. You may be able to get away with the Vandas next to the house under the eaves - Keep dry when it's cold, a dry orchid can tolerate a lot more cold than a wet one. Or next to a block wall - it absorbs heat during the day, slowly radiates it through the night. Or plants can be covered at night with a bed sheet.. you could put a string of Christmas lights (incandescent - you want the heat) under there to warm them up a bit.

[Paytyn2flex]

What great ideas!! Thank you!! I will try that, and keep you updated. Again, thanks for being there