Can I soak a pot with media in fungicide?

[JKeys]

I am just wondering if this will damage the plant's root system.

Thanks!

[WhiteRabbit]

Which / what type of fungicide?

[Stray59]

JKeys:
I do this all the time, but I use a mild fungicide (Captan). About three times a year I will soak my orchids in a mild fungicide / Superthrive solution, to give them a boost and make sure they are well protected. Just spraying the top of the media allows for fungus to develop in areas that are not reached by the spray or trickle-down. By soaking I know that all the media and roots have been treated.
I would suggest against using a copper based fungicide. If you have an orchid that likes to have moss growing on the top, such as a Sophronitis coccinea, the copper fungicide will kill such; I just don't trust it. There are other fungicides that are probably too strong for such, so I would use a mild solution no matter what. Again, like whiterabbit says, it depends on what you use.
Steve

[Wild Orchid]

That's a very interesting question!

A link recently suggested by another OB member for Physan 20 usage also instructs to soak the media.

Physan 20 Orchids

I often wonder also if I could soak a newly bought Phal in both Physan and seewead at the same time, or if there's an order in which one should be applied first.

Lilia

[Stray59]

By the way - I meant to mention this. I don't soak plants in the same water over and over - even though I THINK I have a clean collection, the chance of transferring a disease is just too risky. I just wrap the pot with foil and fill the pot with solution, let it soak and then dump the "waste" on my garden. Captan and Superthrive has no interaction with the foil, but some chemicals do, so you can use plastic wrap or a very deep bowl that is just a little larger than than the pot. This way I do not waste a lot of RO water or fungicide / fertilizer.
Just something to think about!
Steve

[Jayfar]

Isn't the fungicide also going to kill off the beneficial mycorrhizal fungi as well (not to mention other beneficial microbes)?

I think yes, per this other extensive thread on OB:

Beneficial fungus....?

[Stray59]

As far as killing off good fungus - yes, perhaps it does, but this is a method I have used for over 35 years, and I have noted no problems. I have not had a fungal infection in my collections for the last 10 years that I am aware of, with exception to two plants that arrived with the fungus already active in the media. I lost both because I was not able to get the infection stopped in time.
I do need to correct my original post - I have used this method up to three times a year - I do try to do this at least once to twice a year for all my orchids, and if I have a situation, such as mildew growing on the pot, I will use this to as needed.
I feel that the loss of beneficial fungus is a sacrifice I will make for the better overall health of my plants. Again, this is my method and others will have their own experiences; having worked in several greenhouses I can attest that an unchecked fungus can wreck your collection very quickly, whereas the development of "good" microbes can be rebuilt in the media rather easily through the use of organic fertilizers. Also, I am in agreement with the statement in the thread that states the mycorrhiza is definitely important to seedlings and orchids which are not able to produce chlorophyll, but not as relevant to the adult orchids which I have. And certain rather touchy species (such as the Ghost orchids) will need the fungus to create the sugars it needs, but these are not orchids that I grow.
I know of no commercial greenhouses that do not regularly treat for fungus; I guess my thought is that if it is good enough for the pros it's good enough for me.
Again, this is only my method - everyone will develop their own. But to me, prevention is better than a cure anyday...
Steve

[euplusia]

An epiphytic orchid in the wild needs a whole ecosystema of cyanobacteria, several types of fungi, lichens etc. for the support of water and nutrients. A potted plant needs more or less regular watering and fertilizing carried out by a skilful grower.
A fungizide can either work preventive / prophylactic by contact as is the case with copperoxychloride. Or it is taken into the phloema and xylema, transported up and down inside the plant and works systemic. This is the case for example with Metalaxyl.
It is very common for professionals to add a systemic fungicide to the soil in the process of propagation of plantlets and also orchids. But it is important to limit its use to not more than twice a year or so according to the usage sheet, for example because of stunted growth.
Of course you can soak your pots in water with a systemic fungicide. In a specific case you can ask in advance experts if it is well-tolerated by the plants.

[JKeys]

Thank you all-I have some physan 20 that I will use with this method.

[Wild Orchid]

Originally Posted by Stray59

I just wrap the pot with foil and fill the pot with solution, let it soak and then dump the "waste" on my garden. Captan and Superthrive has no interaction with the foil, but some chemicals do, so you can use plastic wrap or a very deep bowl that is just a little larger than than the pot. This way I do not waste a lot of RO water or fungicide / fertilizer.
Just something to think about!
Steve

Hi Steve,
Can you kindly explain this part again, please? I've been thinking about the foil wrapping or plastic as you mentioned but I'm not sure if I really get the point about saving RO water and fungucide this way.
Thanks!

Lilia