Hello from HUMID Tampa, Florida! - Orchid Board

shanlon · #1 10-22-2007, 02:14 PM

My name is Susan. I'm new to this forum - in fact, new to any forum. I have a small collection of orchids - mostly cattleyas - with some den/phals, oncidiums and phals thrown in. Basically, I have the assortment to hedge my bets that something at some time will always be in bloom.

I am relatively new to orchid collecting in the past several years. I'm kind of at a "frustrated" place here - have enough info to be dangerous. I have attempted local Orchid Society meetings and ask plenty of questions - think I'm on the right track - and then some "new" problem arises.

Currently it's fungus - hence my title. Can anybody offer suggestions on what they use? I have been using Physan weekly on a Vanda which was struck with a fungus after some heavy rains. I caught it early but even with treating the plant, it's continue its downward demise. I am so upset because I thought the Physan would work (recommended by nursery). It was a $60 plant and gorgeous. I don't even know if it can be saved.

Any thoughts would be appreciated

cb977 · #2 10-22-2007, 03:15 PM

Hi Susan

Welcome to Orchidboard

I'm in Spring Hill so I know exactly what you mean by HUMID...yuck! Today's a really bad one

When I see the start of something that doesn't look good, I give my plants a spray of Listerine (not the minty one)...if it needs more than that, I've used Thiomyl and it works really well.

Have you been to the Tampa Orchid Society? They have a nice club with some very good growers as members.

Ross · #3 10-22-2007, 03:35 PM

Quote:

Originally Posted by shanlon

My name is Susan. I'm new to this forum - in fact, new to any forum. I have a small collection of orchids - mostly cattleyas - with some den/phals, oncidiums and phals thrown in. Basically, I have the assortment to hedge my bets that something at some time will always be in bloom.

I am relatively new to orchid collecting in the past several years. I'm kind of at a "frustrated" place here - have enough info to be dangerous. I have attempted local Orchid Society meetings and ask plenty of questions - think I'm on the right track - and then some "new" problem arises.

Currently it's fungus - hence my title. Can anybody offer suggestions on what they use? I have been using Physan weekly on a Vanda which was struck with a fungus after some heavy rains. I caught it early but even with treating the plant, it's continue its downward demise. I am so upset because I thought the Physan would work (recommended by nursery). It was a $60 plant and gorgeous. I don't even know if it can be saved.

Any thoughts would be appreciated

Welcome. My sister and dad live in Lutz.

Physan 20 is still the go-to for fungus-related treatments. The thing is, while it is pretty strong, it is very difficult to get rid of fungus (if it is even possible). I grow lots of minis in a very humid terrarium (90+ humidity) misted many times a day and I have lots of fungus that grows over the mounts. I scrub the areas with a small wire brush and spray daily with Physan which slows down the progress, but nothing seems to get rid of it. I'm not aware of any alternative treatment safe to use with orchids. Good luck and just keep spraying.

LauraN · #4 10-22-2007, 04:04 PM

Welcome.
Sounds like you've got a good start with your orchids.
Wish that I could be of help for your problem, but I've yet to treat my orchids with any products...I do keep fans running on my day and night to try and circulate the humid air and that seems to help, as I haven't had a fungus problem yet.
Good luck with your growing, Laura

shanlon · #5 10-22-2007, 04:32 PM

I knew I would meet fellow growers in the area. Yes, I'm a new member of the TOS and have learned a lot! I grow my orchids outdoors in a pool cage or under a tree where there's plenty of air circulation. The problem with my fungus is it always seems to be the destructive kind - one day the plant is healthy, the next, yellow spots on the leaves (with halo) and then kapput! That's an interesting suggestion with the listerine. I think it's wise to rotate because the plants seem to build up an immunity. The grower where I purchased my vanda uses Physan in their greenhouses - and it was grown under very high light. While I had mine under a tree, it was still receiving high light - but not as high as the nursery. I've read that these fungus spores which are present but dormant in high-light conditions cab become active in lower light levels. Does this make sense?

Thanks!

Ross · #6 10-22-2007, 04:37 PM

Quote:

Originally Posted by shanlon

I've read that these fungus spores which are present but dormant in high-light conditions cab become active in lower light levels. Does this make sense?

Yes. High light generally means lower humidity (not always). High light in shade is NOT equal to high light sun. Also radiation from sun (UV) probably does in lots of fungus spores.

Leisurely · #7 10-22-2007, 05:40 PM

Physan is a disinfectant and works as a preventative and is not a cure. Thiomyl is a systemic fungicide that should kill the fungus and provide some systemic control. Two other very inexpensive but good fungicides are Dithane m-45 and Captan. You should be able to find them at your local Ace Hdwe. under the Hi-Yield brand.

shanlon · #8 10-22-2007, 05:47 PM

Thanks! This is really helpful. I hope I can save this vanda.

Ross · #9 10-22-2007, 06:00 PM

Quote:

Originally Posted by Leisurely

Physan is a disinfectant and works as a preventative and is not a cure. Thiomyl is a systemic fungicide that should kill the fungus and provide some systemic control. Two other very inexpensive but good fungicides are Dithane m-45 and Captan. You should be able to find them at your local Ace Hdwe. under the Hi-Yield brand.

Thanks, I forgot about the Thiomyl. For rot in a plant, this works great. For normal fungus it does not. Surface fungus is better treated with Physan which will work not just as a preventative but as a currative as well.

gixrj18 · #10 10-23-2007, 12:48 AM

Hello Susan,

I'm Jasen, I live in Holiday, Fl...not too far from you. I agree with Jerry & Ross, airflow is the biggest key.... I have fans everywhere. I use the Physan for preventative maintainence, but if I'm trying to kill a fungus that has already set in, I spray it down daily with copper fungicide (which can be found at Home Depot) until it stops spreading. I cut away any really bad spots and Isolate it for a while. If yours are hanging beneath trees (especially oak), they have a steady supply of algae and fungus spores, every time it rains. So you should try to give them fungicide regularly, in the summer time.