I have a beginner's question. Several of my plants (an oncidium and an
odontoglossum) have developed black spots on the leaves. I gather from what
I've read here and elsewhere that Physan spray may be helpful. I have the
physan; what dilution should I use? The label says 2 teaspoons per 20
gallons. That's the weakest dilution I've seen. In looking at various
sources on the web I see dilutions as high as one tablespoon per gallon, and
everything in between. It seems that stronger dilutions are appropriate for
use on non-plant surfaces (e.g. greenhouse benches, etc.), but the
recommendations for what to use on the plants themselves are still all over
the place. What's commonly done by posters on this group? Thanks in advance
for your help.
Chuck B.

I use about a teaspoon per gallon.

Before you spray though, be aware that some leaf spotting is a common
occurrence in thin-leaved plants grown in insufficient humidity, so spraying
might not be your answer...
--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!


"C. Berlin" wrote in message
news:n0g9j.3656$DO.1203@trndny08...
I have a beginner's question. Several of my plants (an oncidium and an
odontoglossum) have developed black spots on the leaves. I gather from
what I've read here and elsewhere that Physan spray may be helpful. I have
the physan; what dilution should I use? The label says 2 teaspoons per 20
gallons. That's the weakest dilution I've seen. In looking at various
sources on the web I see dilutions as high as one tablespoon per gallon,
and everything in between. It seems that stronger dilutions are
appropriate for use on non-plant surfaces (e.g. greenhouse benches, etc.),
but the recommendations for what to use on the plants themselves are still
all over the place. What's commonly done by posters on this group? Thanks
in advance for your help.
Chuck B.

"Ray B" wrote in message
news:Kqg9j.875$L91.250@trndny05...

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!

What is the exact URL for the plants you have for sale? I got lost on the
site.

Thanks

Thanks, that's useful. I always value your comments here. Coincidentally,
my first meeting at the Pgh. orchid society was the day you came to talk.
However, my daughter had just unexpectedly gotten engaged a few hours
before, so I felt the need to go home and join the family celebration and
was unable to stay and listen. Nonetheless, this online group is a fine
source of learning, and my knowledgebase is slowly expanding. Every time I
go to a meeting here I also come home with some new insight as well. My
small collection of a few dozen plants (window light only) is in way better
condition now than it was a few years ago.
Thanks, Chuck B.


"Ray B" wrote in message
news:Kqg9j.875$L91.250@trndny05...
I use about a teaspoon per gallon.

Before you spray though, be aware that some leaf spotting is a common
occurrence in thin-leaved plants grown in insufficient humidity, so
spraying might not be your answer...
--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!


"C. Berlin" wrote in message
news:n0g9j.3656$DO.1203@trndny08...
I have a beginner's question. Several of my plants (an oncidium and an
odontoglossum) have developed black spots on the leaves. I gather from
what I've read here and elsewhere that Physan spray may be helpful. I
have the physan; what dilution should I use? The label says 2 teaspoons
per 20 gallons. That's the weakest dilution I've seen. In looking at
various sources on the web I see dilutions as high as one tablespoon per
gallon, and everything in between. It seems that stronger dilutions are
appropriate for use on non-plant surfaces (e.g. greenhouse benches, etc.),
but the recommendations for what to use on the plants themselves are still
all over the place. What's commonly done by posters on this group? Thanks
in advance for your help.
Chuck B.