Ptychogaster or Snow Mold - Orchid Board

JennS · #1 06-23-2008, 11:49 AM

On nearly all of my plants that are on the ground (no orchids are directly on the ground) and some that are not this stuff appears that I have researched and determined to be called snow mold or ptychogaster. Anyone ever had issues with this on their orchids? It looks like webbing almost and usually starts around the drainage holes in the bottom of the pot. Any idea on how to ward this stuff off or get rid or it if it appears. I think it took the life of a new evergreen dendrobium that I got as a gift so now I am not too happy with this suff!

JennS · #2 07-01-2008, 03:19 PM

I am really starting to get concerned about this stuff. I repotted most of my orchids on Sunday and at least half of them had snow mold in them. I also just noticed it on one that I keep inside and I don't know how one that is indoors would get it.

I keep my indoor orchids on trays with those little glass beads that are used for decoration and anchoring cut flowers in tall vases. I try to keep the water away from the bottom of the pot, so I don't think it is too much moisture.

I am concerned because I read that it will eventually kill the plant by stealing the mositure out of the medium.

Oh another thing, I have only noticed it in the plants that are in bark. The ones in spaghnum have seemed to be safe. I have also noticed it around the base of some other types of plants (I think mostly succulents and cacti) that are sitting on the ground on top of mulch. The mold doesn't seem to really be able to spread up into regular soil very well though.

Any comments or ideas would be greatly appreciated. Thanks!

addictedcountryman · #3 07-01-2008, 03:29 PM

hi
can you post pics? although you are very detailed about your concern, i think i know what you are talking about. when you repotted, did you spray your roots with peroxide? i had a problem with a white fuz and i repotted. it hasn't come back, but i think a new pot and media would have helped you out. maybe try moving your orchids away from the humidity trays?

JennS · #4 07-01-2008, 03:48 PM

I will snap a picture tonight and post it in the AM.

I did repot all of them in fresh media, and most of them in brand new pots. I did not know about the peroxide, but I can go back and do that if needed. I would be sad to waste all that medium, but if it needs to be done, I will do it!

The orchids that are on the humidity trays are generally fine, except for one. Mainly it seems to attack outdoors. I do have all the orchids pretty closely together and they are sitting on a bench so they do drain, but could probably use more circluation. I have been trying to figure out a better stand idea, but the last one I had the property owner did not like and made me take it down. The bench allows for me to have them somewhat hidden. I will just take pics and post them tomorrow...

Thank you for the interest though!

JennS · #5 07-25-2008, 09:28 AM

I am bringing this post back up because 1) the snow mold is still attacking even after repotting everything! 2) I finally got some pictures...

So, here are the pictures. I decided to check out my phals because they both seemed Ok, but the spag has been staying so wet. The roots themselves look very good, but the snow mold was back attacking them. It is very strange...this time it seems to have started inside the root ball rather then coming up through the opening at the bottom of the pot. I am going to try to post these pics now, so bear with me if it takes a couple of tries.

JennS · #6 07-25-2008, 10:10 AM

This picture thing is not as easy as I thought! Hopefully this will work...

JennS · #7 07-25-2008, 10:11 AM

OK, here are a few more...

JennS · #8 07-25-2008, 10:16 AM

Ok, so pic #1 is of the plant in question, it is the larger of the two Phals pictured. The other one has some snow mold too, but the pics of the roots are of the larger one.

#2 is the roots from the outside, nice and healthy looking

#3 some nubbins, but a glimpse of the snow mold is visible

#4 shows the snow mold in the middle

Next post:
#1 and #2 more views of the snow mold on the roots

#3 and #4 snow mold growing on top of mulch near orchid growing area

#5 shows the view from the bottom looking into the center of the root ball

Thanks for taking the time to look!
q

JennS · #9 07-28-2008, 10:47 AM

Does anyone have any other advice? I did repot with new medium, clean pot and used peroxide on the roots. I also tried to rub away as much fuzz as possible. I recently moved a pot that I left outside with a bunch of old medium that I had dumped in the pot when repotting. The pot with the old medium was sitting on the ground on top of mulch and it had a huge new growth of the stuff underneath. Will try to get another pic of that too. Any other advice will be greatly apreciated.

cb977 · #10 07-28-2008, 11:11 AM

I've received plants by mail that sometimes have snow mold. It only happens in bark mix, I think it's because of the bark breaking down. It's just one of the many reasons I switched all the chids out of bark and only use aliflor and for some, sphag.

Whenever I've had the problem, I removed the chid form the old stuff, sprayed it well with Listerine and then repotted into aliflor which does not break down.

I'd hate to say it all needs to be repotted again but I wouldn't comfortable knowing the mold is there.

Hopefully, somebody else can come up with a better solution