In search of perfect foliage...

[Dorsetman]

Its difficult to get and keep, on plants which have been in a large collection for any length of time especially in a greenhouse in a temperate zone - like England. Inevitably there are days in the winter - sometimes spells weeks long , when the temperature never rises above the stat' settings day or night - and someties falls below as today when a gale blows up the English Channel - 60 mph winds, and the mercury rests on 9 degrees at midday. There are heavy showers - one of hail this morning , so humidity is too high . This encourages black spots to develop on th leaves , if not hairy botyritis.
I think a routine spraying say monthly, with a plant disinfectant, may help. We can't get Physan any more, and Phytan has never been sold here.
I read about Citrox - these disinfectants are really designed and marketed for disinfectang say plant tunnels between crops, rather than the plants theselves, but Citrox at 25ml per 100 litre water ( sounds weak ?) has been suggested for seedlings.
I'm thinking of trying it . Any experience anyone,? Any other suggestions ?

[mauraec]

Geoff - why can't you get Physan any more? I ask because we still can and I'm going to stock up just in case. I use Daconil on my orchids - they seem pretty okay with it - haven't killed one with it yet, anyway. Because of my getting my collection back (from the woman starring in "The Case of the English Greenhouse Murders") either dead as doornails, or covered with fungus, rot, and all sorts of wonderful things, I have been doing a lot of disinfecting. I alternate between organic (neem oil, garlic and rosemary oil, sesame oil, cinnamon, etc) and the real chemical bombs. I found this table to be pretty helpful: http://www.staugorchidsociety.org/PD...idDiseases.pdf. Good luck - I'm still working on mine plant by plant, but slowly, it's getting done. Hope your are recovering from their ordeal as well.

[Dorsetman]

Geoff - why can't you get Physan any more? .

They have never done the necessary product testing (too expensive) to get the needed licence to satisfy the EU bureaucracy ; it's not even that no-one sells it in Europe - it would be positively illegal to sell it !.
I have thought of visiting New York ( for example) to see the Orchid Show (again), and bring some back , but its pretty heavy , obviously more than 10lbs per gallon, and i wouldn't want the expense of that trip every year - so I decided that was not practical. But I can't see any reason why the sale should be stopped in USA. In my experience its the best - so keep on using it . I wish I could. It's a good alternative I am looking for .

[Cjcorner]

A friend of ours has a business where he "loans" out orchids to doctors offices and such that like fresh plants. He situated his watering heads so that they are below the shelf. He says this keeps the leaves looking lovely and keeps infections and such at a minimum. As he has a humongous greenhouse and thousands of plants to constantly maintain it must work well. I saw pictures of his greenhouse and it was wall to wall perfect looking dendrobiums. No bad leaves. If and when I install a watering system I'm thinking of using that sort of set up.

[cakedaddy]

There are products available in the food service industry for the purpose of surface sanitation. If I am not mistaken, it contains exactly the same compounds as physan. I will have to double check tomorrow.
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[Dorsetman]

There are products available in the food service industry for the purpose of surface sanitation. If I am not mistaken, it contains exactly the same compounds as physan. I will have to double check tomorrow.
Posted via Mobile Device

Indeed there are, and in fact I have been buying and using them- several different ones for the couple of years since my Physan supply was used up ; the problem is that there is no indication of the sort of dosage useful for my purposes. the dosage for cleaning a food preparation surface, subsequently allowed to dry off ( and evaporate ? ) for 24 hours before re-use, could well damage an orchid - I tried that dose on a few and they lost all their leaves... but am I now diluting too far ? That is the problem. How to know ? Which is why a horticultural industry product might be more useful.

[mauraec]

That is the problem. How to know ? Which is why a horticultural industry product might be more useful.

Geoff, did you look at the link I posted in the 2nd post on this thread - it has a comprehensive list of all kinds of orchid 'cides and you might find it at least of some use. Here is the link again: http://www.staugorchidsociety.org/PD...idDiseases.pdf. It may be useless, but it seemed pretty comprehensive to me. Hope it helps.

[Dorsetman]

Geoff, did you look at the link I posted in the 2nd post on this thread - it has a comprehensive list of all kinds of orchid 'cides and you might find it at least of some use. Here is the link again: http://www.staugorchidsociety.org/PD...idDiseases.pdf. It may be useless, but it seemed pretty comprehensive to me. Hope it helps.

I guess I read that message too quickly, so no, I didn't look at the l;ist - but IO';m going there now....

[Dorsetman]

Hi Maura,
I followed up every single one of the items listed as fungicides and bactericides – the only one I could buy in UK is Neem Oil , and I have used that in the past and been impressed only by the disgusting state of my spray equipment , which I had to scrub out with hot water and detergents and goodness only what else , to get clean. If those kinds of traces were left on the plants , the foliage would hardly be improved, but in fact I found the deposits on the plants very patchy ; hit and miss. Obviously oil and water don’t mix, and trying to keep the stuff in suspension whilst the spraying proceeds is the problem, apart from which it works only as a contact insecticide – so if the beasties miss being sprayed, they are OK. And it has no effect on bacteria and fungal stuff anyway – which is what does the marking I am trying to get rid of.
No, the problem with the listed stuff is often that it is copper based , and I think there is a blanket ban on the sale of copper-based chemicals to ordinary citizens. All the good old remedies – Cheshunt Compound, Murphys Copper fungicide etc have gone.Illegal to sell them.
Some of the other stuff on your list IS available, but only to licensed registered (large scale) traders.This is what we call ( and hate ) “the nannie state” – “they”- the bureaucrats in Brissels want to save us from harming ourselves accidentally, so they ban the sale of anything which can kill bugs or bacteria – just suppose we go mad and drink it , for example….

However, thanks for trying.

[mauraec]

So sorry neem oil was the only available one in the UK - I can't believe you can't get copper-based sprays - is Daconil copper-based? I use that on particularly tough fungus cases. Are you sure it's only the health care system that is socialized over there? Sounds like you have Big Brother the size of King Kong watching out for the idiots who need to be told what to take internally and what not to. But, then again, never overestimate the ability of most people to READ THE DIRECTIONS....

I find neem oil pretty gucky too. I don't have your equipment, but I find that I end up wiping off the leaves one by one when I use it - not very efficient.


You know, there may be a vast conspiracy out there to deprive successful growers of essential materials. Perhaps you need to start a petition and go rap on the door of your MP.