I recently switched several plants from bark to a mix of lecca and rock wool. Several are starting to grow mold on both the lecca and rock wool. I am suspecting the source might be some cheap rockwool from Amazon. But strange that it is growing on an inorganic medium? I have physan 20 but the directions says to spray the plant, nothing about drenching the medium. But can I and at what strength? I also have biosafe H2O2. Can I use that as a drench? Any other suggestions for getting rid of mold? Thanks for any thoughts.
Mold on medium
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Simpliest with what you have would be to repot - soak fresh medium in physan before potting. For a drench banrot or thiomyl might work and be reasonably priced. If I don't treat right away I usually have some persistence in the medium. It seems like some molds are easily eradicated and others not at all. I had a mold a I was chasing in potting media this year and I ended up getting several compounds and tank mixed them. That worked well but was expensive. If rot gets into the roots then it's more of problem. Heritage is available in smaller containers on amazon and that could also be effective.
Have you applied anything anything other than inorganic fertilizer?
If it's only growing on the surface I'd spray it with alcohol.
If it's only growing on the surface I'd spray it with alcohol.
It’s hard to say from a photo, but it is unlikely to be mold.
Did you wash or otherwise pretreat the LECA? During manufacturing, “binders” are added to the raw clay to get it to roll up into little balls and to retain their “green strength” during subsequent handling and firing.
Depending upon the binders used and the firing conditions, there may be inorganic salt residues retained in the pellets. If they are water soluble, they will make their way to the surface as the pellets dry, forming a fine, needle-like “fuzz” that can resemble mold.
Flood the living hell out of it whenever you water, and the residue will be washed out of the pot over the next several weeks.
Did you wash or otherwise pretreat the LECA? During manufacturing, “binders” are added to the raw clay to get it to roll up into little balls and to retain their “green strength” during subsequent handling and firing.
Depending upon the binders used and the firing conditions, there may be inorganic salt residues retained in the pellets. If they are water soluble, they will make their way to the surface as the pellets dry, forming a fine, needle-like “fuzz” that can resemble mold.
Flood the living hell out of it whenever you water, and the residue will be washed out of the pot over the next several weeks.
To me that looks more like some sort of salt creep. I would expect an homogenous coating from fungus but this creep seems to follow the water. I think Ray is correct.
If this is a a fungus then it must originate from the plant and as the plant is healthy I wouldn't be concerned about it.
If this is a a fungus then it must originate from the plant and as the plant is healthy I wouldn't be concerned about it.
That's why I asked if some kind of organic fertilizer or stimulant was applied.
These plant looks healthy, so why should mold come from a healthy plant ? Mold or in general fungus spores are omnipresent in the air ... they need three things to germinate ... moisture, the right temperature and organic substance for food e.g. dust on the surface.
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Wow, I love all the experience and info on this forum and everyone's willingness to share. Thank you!
Yes, I have recently added urea to my watering - and I think a little too much. I am also pushing my water solution with oxygen - not certain how much actually dissolves in the water. I've also watered once with kelpak but noticed the problem before this watering.
Maybe the rock wool retains moisture long enough that it provides an ideal habitat for mold? I wonder if I should go to straight lecca for all my paphs? I know you use a unique mix for your medium and water very infrequently. I decided, in part, to grow SH because we travel a lot and it limits my ability to water frequently.
This is definitely mold. This is my only phrag and it looks healthy but when I repotted it after bringing it home I found a rotted root ball under the crown. I left for a month and when I came back it obviously had mold on the medium. I isolated it and will see if I can get rid of it with some sort of fungicide.
Ahhh, this makes sense. I have been seeing this start on a lot of my pots. As TyroneGenade says, it follows the water line. It seems to be growing thicker so I started thinking it was the same mold starting to grow. But it does look more like a salt build up. I will start flooding them like hell. 😅
Whatever you do I would not beat around the bush - waiting around gives more chance that something secondary might infect the roots.
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