Snow mold
 

I seem to have a pretty good bit of snow mold going on my big catt. I've already got plans underway to repot it into s/h (thanks Ray), but in the meantime while I'm waiting for my supplies to arrive, would it be a good idea to give it a hit of physan? The way I see it, 2 doses (one now, one when I repot) is more likely to take care of the problem than just one, but I don't want to hurt my plant either.

I know the main issue is getting rid of all the infested media, as the mold is primarily infesting the bark, not the plant, but I just thought this might kick-start the process by reducing the pathogen load a little while I'm waiting for supplies, and would of course give me the benefit of a second dose. Of course, if I'm off base here, let me know, because like I've said before, I'm pretty new at this!

Thanks in advance!

Why does the mold grow? Over watering??

I found mention of it briefly at this link:

http://orchidweb.org/aos/MessageBoar.../ROA200605.PDF (don't know if you can get there from externally, you may have to log on to the orchidweb.org forum and then go here http://orchidweb.org/aos/MessageBoar....aspx?tid=3374 )

From what I can tell, it's a result of the bark mix breaking down more than anything, but I could be wrong.

Anyone had any expereince with this problem???

Thanks!!

I just read the little article you sent. For those who can't see the link or don't want to look for it, it says:
Snow mold is a fungus called ptychogaster. It spreads through potting medium, often visible on top of the medium you are using (tree fern or fir bark) and around the drain holes of you pot. It leads to drying out of your orchid as the mold starts to grow on the roots of the plant and is water repellant, so water barely reaches the roots.
According to the article you repot the plant, remove and destroy all mold and potting media. Remove from the roots and treat the roots with Physan or RD20.

It be interesting to see what other people with experience have to say.

Thanks for the link Dr. Scott.

update 1: yesterday I gave the catt a good shot of the physan. I mixed up a quart of water with 1/2 tsp of physan, then poured it all over the plant. so far everything seems ok.

I would suspect that the snow mold is a result of the media breakdown AND the resulting lack of air within it.
I would give the entire pot an extended dunk in a Physan solution to allow it time to fully infiltrate the media.
If the mold is indeed water repellent, a small amount of plant safe detergent may be in order to help reduce it's surface tension and allow the Physan to penetrate.

that's going to be phase 2 of my plan...

as soon as I get my s/h kit, I'm going to soak the plant in concentrated physan (1 tablespoon/gallon) for 5 min, then unpot, remove all signs of the mold, divide, rinse with concentrated physan, and repot in s/h. they actually recommend something like this on the physan product insert as just part of the routine repotting process.

sound good?

ps, further update: I just looked at the visible areas of mold on the surface of the medium, and around the drain holes, and they have definitely regressed since undergoing phase 1. so I think it's helping to at least kick-start the process.

http://www.orchidboard.com/community.../snowmold1.jpg

http://www.orchidboard.com/community.../snowmold2.jpg

(edited to add the 2 pictures)

Keep us updated. All this is new stuff to me.

Biochemist mode ON:

Physan appears to be a surfactant as is, so I don't think any added detergent is necessary. This is evidenced by the viscous character of the concentrate as well as the ready foaming when mixed with water. The structure of it (an aromatic amine) also leads me to the same conclusions.

Chemist mode OFF.

I think the real solution is going to be removal of all the old potting medium (standard orchid bark mix) and debridement of any affected areas of the roots. The Physan should just help the process along by getting rid of smaller collections of fungus which are retained, and the first dose appears to have had the exact effect I wanted: reducing the total pathogen load and slowing the growth of the fungus some. But we'll see. The real test will be next week and thereafter once it has a chance to reestablish in its new pots.

Very impressive ;) ........are you a biochemist?

Let me know how the s/h works with you plant - I also ordered some supplies from Ray (yesterday actually) to move my phals into. If all goes well, I will probably change most my plants (catts, paphs, phrags) to it.

I am really interested in the use of it for seedlings, as I have many flasks.

Are you going to use K-L-N upon repot?

sortof. I majored in biochem in undergrad, and just finished my MD a few weeks ago. but my wife is in her 5th year of her biochem PhD. So there's still lots of biochem in the family.

I'm gonna go straight "by the book" for the s/h, at least at first. I'll keep you posted as to how it goes.

Congrats on you MD. Sounds like it was well deserved!

update the next
 

next update: supplies have arrived. rinsed the prime-agra with tap water, then put it in a bucket with 1 tsp/gallon KLN. will divide and pot the catt tonight.

repotting update:

soaked the plant in 1 T/gallon physan, then unpotted. turned out to be a bigger pain that I thought due to adherent roots, so I went ahead and just cut the pot in half with a utility knife. worked great.

Once inside, I discovered that the problem was worse than I had thought--the media was almost completely decomposed, such that roots could only grow into the top 1/3-1/2 of the pot because it was so dense below that. but the roots actually looked relatively good to my novice eyes--thick, firm, pliable. So I didn't have to trim too many roots, although I did have to cut through a bunch to divide it. Division turned into more of a problem than I had hoped too...ended up making 3 divisions, then putting them into 2 pots just because of where the cuts lined up. But both pots have several new growths in them, some of which I didn't even know about before repotting because they were hiding amongst this overcrowded plant.

Cleaning the roots was a big pain, because there was a lot of rotting bark in between all of them, but I worked slowly and kept washing the plant off with water and it seemed to go ok.

Actually potting them was relatively simple: just hold the plant roughly in place and use the other hand to scoop primeagra on top, then shake it until it settles, repeating until it's full. I then topped them off with a bit of water and called it a night.

Pictures are here: http://www.orchidboard.com/community...ry.php?cat=521

If you go to my gallery via the button in my signature, you can also see a "before" picture of the big plant a few weeks ago when it was in flower.

Very cool pics. It helps us all out.
How much of a setback to the plant do you think it will cause after cutting the roots? I'm always afraid of killing them if I cut the roots.

As long as the plant is in good condition and active growth, set back should be minimal.

Great info and pictures Scott. Thanks for the update. BTW, what is the Catt that you repotted?

http://www.orchidboard.com/community.../cattleya2.jpg

It's Laeliocattleya Ken Stromsland 'Eric' (Arlene Marie x Hausermann's Pride). Great fragrance too!

I didn't end up cutting many viable roots...just trimmed a few soggy tips until I could see green, and made the minimum number of cuts to make the division, so hopefully it won't set the plant back too much. I'm hopeful that this will actually kick start this plant since the potting media was so badly decomposed.

A lesson I learned from this is that when you buy an orchid, you should ask when it was last repotted. This one had gone way too long from what I can tell.

Scott...thank you so much for the in-depth information. This site has just become an even better place :)
Congrats on your MD...that's quite an accomplishment:cheer:

Okay, so now it's my turn!
 

I got my clear pots today and separated which plants were going into new pots and new prime agra (which isn't coming till tomorrow), and which are just getting a revitalization with new medium and clear pots.
Out of about 14 plants that I did today with bark, 3 of them had the beginnings of mold happening down under!
:shock:
I gave them the TLC they were asking for and begged for forgiveness :_( so hopefully, they'll be fine. The root systems I found were mind-boggling! Thick, long beautiful healthy roots that came so close to being damaged!
I can hardly wait to see what I find when I tackle the rest ;)

I have some recently deflasked seedlings growing in sphagnum. They are getting a fuzzy (mold?) here and there. Should I worry about thes? The seedlings look fine!

I'm not an experienced flask grower, but I sure wouldn't want any mold on my seedlings. Are they getting good air circulation?

No because they were so tiny when I got them I put them in a plastic container with a lid so the wouldn't dry out. They are a little bigger now and look fine except for that. When the container gets moist(water beads on the sides) I open the container and let them dry out a little but they are so tiny I am afraid if they get too dry they will die. They look like tiny bean sprouts!

I've never done this myself, but an idea off the top of my head - why not get a small fish bowl or small aquarium (1 gal or so) and set to container of seedlings on small supports (corks, marbles, stack of coins, anything to get 1/4" to 1/2" verticle over the bottom of the aquarium/bowl) Then add small amount of water to the bottom the the aquarium/bowl. Add piece of glass as lid, but prop it up with a match stick or so at one edge -- just enough to keep up humidity, but not enough to grow mold. Add more supports till you strike (hmmm) a balance. I was just sitting here wonderin' what I would try.

I put all my flasklings out into the open air, no baggie or plastic box treatment for them. So far so good, I've had my Paph viniferum for over a month with no losses, and my tigrinum and tigrinum x adductum are all looking good after a week in the open. I do have high humidity naturally though, between 70-80% most of the time.

In florida? Yeah I would guess that it is nice an humid even for this time of year.

Bean Sprout seedlings
 

Well on instinct I opened the lid to see what would happen and the mold or whatever it is is gone!!:biggrin: I am going to try to be brave and leave the lid off. :shock: Thanks for all the great advice! :idea:

P.S. They are Cattleya Pattini seedlings. Hopefully they will make it!