It sounds like you have some "snow mold"....if allowed to "grow" it can suffocate orchid roots. A dosing of Physan should clear it up and warmer temps in your grow area....molds like it cool and damp. This is only my opinion.
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dear friends,
i started s/h some time back and now i think the plants are establishing themselves rather well. but i noticed there are these moldy webs on the stone surfaces and also in around the drain holes. what do you think they are? i do not think they are spider/mites webs, but just moldy threads. some time back i got some furry molds but after i sprayed with diluted bleach i got rid of them. now i got this.
is there a safe way to get rid of them, are they harmful to the plants?
chung
It sounds like you have some "snow mold"....if allowed to "grow" it can suffocate orchid roots. A dosing of Physan should clear it up and warmer temps in your grow area....molds like it cool and damp. This is only my opinion.
Never seen anything like that on my plants & i have over 60 in s/h.
Airflow & temps may be the culprits(lack of both).
yes, i went on to discover some people mentioned this problem before here in this forum. i think some mentioned that it only appears on some pots but not others. this is the case with me. i have 4 pots of s/h and it appears on 2.
i sprayed some diluted bleach on it and flush through the pot with the bleach also. i hope it helps. does bleach work the same as physan 20?
chung shih
Chung, without a pic I can only guess at this, but if by "threads" you mean very thin, almost invisible filaments, that might be Mycorrhizae, a type of fungus that tends to grow around a plant's roots. It's much more noticeable on phals that have been potted in Pro-Mix or some other type of fine media, where if you unpot the plant, you'll notice tiny bits of the media hanging onto the roots by almost invisible webs or threads.
Mycorrhizae aren't harmful, and for some types of Paphs and Cyps, are actually vital as a source of nutrients. If that's what you have, no worries. You can leave it on or get rid of it, as you please.
Be very careful with using bleach or Physan to flush the root system. Dilute it to a concentration of no more than 5 percent, and BE SURE to flush the pot for several minutes with clear water within 24 hours of applying. Don't forget to do this, or you can severely damage / kill your plant!
dear louis,
thanks for your reply. yes, a picture would be best. currently i have no means of taking quick pictures for posting. the filaments are not tiny enough to be unnoticeable. i can see them on the surface of the media and also at the drainage holes. when i spray on them, the fluid stretches across the web of thread. they appear sticky as i try to remove them. it does seem like spider web where pearls of water droplets hang from. but the plants seem to be healthy with no mites or spider.
hope it is not a big deal.
yes, i am not too sure about the bleach although i think you mentioned some grower flush their plants with bleach regularly?
chung
Chung, the growers who use bleach spray the leaves with it as a disease preventative, using very dilute concentrations--chlorine is a very strong oxidizer and can be deadly to orchids. Those growers flush the pots afterward with water even though they never let the bleach solution deliberately contact the roots. If you're going to pour something through the roots, I would definitely go with Physan rather than bleach, and still flush the pots out very well afterward.
If you're seeing webs like tiny spiders might make, you'd be much safer diagnosing the problem as insect-related and mixing up some insecticide to pour through rather than bleach or Physan, which can do a lot more damage at high concentrations than a few little insects any day....
There are products that are used to treat both insect and mold infestation.
I would un-pot this plant give the roots a good rinsing off with plain clean water. repot in a clean new pot with new medium and treat with Physan. and try to move it to an area with better circulation and warmer temp.
good luck
thanks matthew and louis for your advice. i poured some diluted bleach - like 1 tsp in one gallon - into the pot and then flush it with lots of water. the webs are gone. like disintegrated i think,but only the next day i checked, not immediately. so it may be mold afterall. but today, i found new furry mold,another kind - sigh. this whole thing is a mold lab - hahaha...
i am hesitant to unpot the plants because they seems to be growing well, and one of them is developing flowers. would repotting affect the flowers?
matthew, i got curious about your website link and went check out. i found pics of chinese cymbidiums. may i know ehre you buy them from and what are your expereinces with them? that is the next kind of orchids i would like to have.
thanks... the cymbidium's were both gifts and i am unsure of their origin.
try to search for cymbidium on google. or check out some of the vendors at this link.
http://www.orchidwire.com/Vendors/1/United_States.html
i wish you good luck w/ your mold problem. remember mold likes cool damp conditions. so if your orchid is in a windowsill in upstate ny in the winter it may be 70 deg in the rest of the house but there is a micro climate that may be (10deg or more) cooler near the glass. where exactly is this plant in your home? I.E.(in a windowsill on the east/west/south side of your house, or under grow lights/do you have a fan for circulation?) i wouldn't be too concerned w/ repotting damaging the flowers or buds (they aren't open yet right?)
so long as you are carefull. it may be more damaging to flush w/ bleach.
good luck,
matt