# Using Physan as a drench?



## silence882 (Sep 11, 2016)

Has anyone ever used Physan as a drench? If so, at what concentration?

The directions indicate it's fine at 1.5 tsp/gal for ornamental plants, but I just wanted to check to be sure. I've got 2 pots with what looks like mold growing in them that I'd like to kill with fire.

--Stephen


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## Ray (Sep 11, 2016)

I have done so, but at 1 teaspoon per gallon. Don't forget that some plants really don't like Physan, which is why I switched to Biosafe Disease Control, which has shown no phytotoxicity whatsoever.

However, the presence of mold indicated decomposition. Treating it is just treating the symptom, not the problem. I'd consider repotting, then treating.


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## silence882 (Sep 11, 2016)

Ray said:


> I have done so, but at 1 teaspoon per gallon. Don't forget that some plants really don't like Physan, which is why I switched to Biosafe Disease Control, which has shown no phytotoxicity whatsoever.
> 
> However, the presence of mold indicated decomposition. Treating it is just treating the symptom, not the problem. I'd consider repotting, then treating.



Thanks, Ray. I just got the plants (2 Phrag. Barbara LeAnn) and noticed the mold pop up, so I repotted. Now the mold looks like it's growing in the fresh mix so it's time for chemicals.


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## abax (Sep 11, 2016)

I don't use Physan, but Cleary's 3336 is a much safer
choice for orchids.


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## Ray (Sep 12, 2016)

Angela, they're for two different applications.

Cleary's is a systemic fungicide. Physan is a topical disinfectant that kills bacteria, fungi, algae and viruses.


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## Ozpaph (Sep 12, 2016)

I, very occasionally, use it at the strength Ray suggests.


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## gonewild (Sep 12, 2016)

I used it once in an ebb/flow system. Added it to the tray water at recommended strength and it damaged small seedlings without any getting on the foliage. Never used it again.


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## Ray (Sep 12, 2016)

Hence my Biosafe recommendation...


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## abax (Sep 12, 2016)

Ray, isn't mold a type of fungi? I've used Cleary's on mold
and it worked very well.

Lance, are you referring to Physan or Cleary's?


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## gonewild (Sep 13, 2016)

abax said:


> Lance, are you referring to Physan or Cleary's?



Physan


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## tomkalina (Sep 13, 2016)

Our experience was similar to Lance's. Sprayed a 10% solution of Physan 20 on a tray of freshly deflasked Phrag. besseae fma flavum 'Fox Valley Gold' HCC/AOS (x self) seedlings years ago (these were the first flavum seedlings produced) and all died within 10 days. A very expensive lesson. We still use a 10% solution to sterilize cutting tools and to paint on plant wounds, but never as a drench.


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## Ray (Sep 13, 2016)

abax said:


> Ray, isn't mold a type of fungi? I've used Cleary's on mold and it worked very well.




Sure, but that's a really expensive way of getting rid of mold!


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## Redtwist (Sep 13, 2016)

Used Physan 20 recently (at slightly weaker than recommended for 'monthly preventative' as per the instructions) to flush through a couple of phals I inherited with bad algae and snow mould. Killed off the problem beautifully in just a few days and no sign of damage to the plants health since.. Never drenched a whole plant though.


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## abax (Sep 13, 2016)

That's o.k. Ray. I've got a 30 lb. bag stored. I got a bit
carried away when it was on sale somewhere or other. The
granular stores quite well. Oh, I remember now...our local
Southern States store orders "stuff" for me since we do a
lot of business there.


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## silence882 (Sep 15, 2016)

Well I just poured the Physan through the media at 1 tsp/gal. I'll report back in a few weeks after I see how it does.


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## Happypaphy7 (Sep 17, 2016)

Physan. never again after using it once some 10 years ago.


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## Erythrone (Sep 19, 2016)

Happypaphy7 said:


> Physan. never again after using it once some 10 years ago.




I agree. I don't use it anymore in potting media or on plant. I use similar products for cleaning the growing area, though.


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## silence882 (Sep 21, 2016)

No change so far. I just hit it with a second dose.

Here's some photos of the mold if anyone has any recommendations for dealing with it:










--Stephen


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## Ray (Sep 21, 2016)

What are the ingredients in your mix? 

Are you sure the fungus is bad? I've seen similar growth in Orchiata, and was told it was a penicillium species that killed other fungi. You could always does it with Inocucor....


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## silence882 (Sep 21, 2016)

Ray said:


> What are the ingredients in your mix?
> 
> Are you sure the fungus is bad? I've seen similar growth in Orchiata, and was told it was a penicillium species that killed other fungi. You could always does it with Inocucor....



One's in bark/perlite/charcoal, the other 2 are in CHC/perlite/charcoal. 

Unfortunately I have no way of knowing what it is. Therefore it has to die lest it spread. 

I'll give inocucor a shot if the second dose doesn't eradicate it.


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## naoki (Sep 21, 2016)

I occasionally see something similar right after repotting, but they usually goes away within a month or so. They eat whatever they can, and the rest is too difficult for them to access. Maybe you can accelerate this process with Inocucor, but yeast (I believe it is one major component of Inocucor?) probably would do the same thing.

If you are paranoid about it, have you tried H2O2? Or the Zero-Tol thing.

Over the summer, I drenched many of my plants with Physan-20 and its equivalent (RD-20, at 1.5tsp/gal or Bemis Humidifier Bacteria Treatment at the similar concentration of the active ingredients) frequently in an attempt to control bush snails. Most healthy plants were not killed, but weak ones died. I used bunch of other chemicals, so I can't pin point the phytotoxicity to Physan-20, but the phytotoxicity of quaternary ammonium compounds (active ingredients of these) isn't too bad at this concentration for orchids. Caffeine is a different matter, and caused major damage to my orchids....


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## Stone (Sep 21, 2016)

silence882 said:


> No change so far. I just hit it with a second dose.
> 
> Here's some photos of the mold if anyone has any recommendations for dealing with it:
> 
> ...



Steven, I think this is a mycelium growing on the CHC or any other ingredients that are not matured enough. It basically feeds on the carbohydrates and when they are exhausted it will disappear but you may have damaged roots by then. I believe your mix needs to be re-considered. (BTW from my trials growing ferns in CHC, it can take 2 years or more before the chips no longer get attacked by this fungus) Sometimes, a drench in Calcium hydroxide stops it as it prefers acidic (and dryish) conditions. It usually does not occur so much if very wet. Bacteria usually take over then. Maybe a competitive bacterial approach might work also?


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## Ozpaph (Sep 22, 2016)

Your mix looks very dense/heavy. 
I dont think CHC helps keep the mix 'open'.
Fixing the mix will probably fix the problem.


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## silence882 (Sep 22, 2016)

This mold came with two plants that I recently got. I repotted, but that didn't solve the problem. I've been using the CHC mix for years with no mold issues before now.


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