"Vox Humana" wrote:
It is most likely a fungal disease. Here is a like to a wonderful
article, with pictures, on diseases of hydrangeas:
http://www.aces.edu/pubs/docs/A/ANR-1212/ANR-1212.pdf

One of the pictures looks like that black spot fungus that grows
on roses.

One of the treatments for black spot on roses is suggested by
mixing a bottle of water with a teaspoon of baking soda and a
teaspoon of cooking oil. I tried that but my squirt bottle tended
to get all choked up for some reason and all the leaves ended
up being cut off.

I had tried some 12-10-5 vigoro tomato food on the roses
with no visible immediate success. I then noticed that the rose
food at the store had a high content of potassium. So i chopped
up four banana peals in a blender and then put the whole goo
into the soil at the base of the roses.

That worked wonderfully. A month later, leaves bloomed, and
a full set of roses started blooming.

Also, I've read that chives will help deter the black spot on
roses, so I've planted some chive around the base of the roses.
I've not had any success at all with planting chives though, so
I cannot say one way or the other if that is a good suggestion
for your problem. But it might be something that you can do
searching via google on by typing in the keywords, the name
of your plant, etc. When I was looking for black spot help for
roses, I was doing searches for "black spot"+rose+organic
and I pulled up a link about the baking soda and cooking oil.
While I can't say that was any help for me, maybe someone
else that has actually gotten a squirt bottle to work with such
a concoction might be able to comment. Since bananas hold
a high content of potassium and I've read some stuff about
using banana peals for potassium I decided to try it and it
worked fabulously. But ALL the leaves with the black spot
were cut off first before I had an opportunity to witness if
it would work while black spot still infected the leaves.

One thing that I keep in mind when is that usually infections
are caused by a deficiency of vitamins or minerals. The same
is true for humans as anyone will tell you that you should have
some kind of vitamin C, especially on long boat rides or visits
to other countries. The folks back in time used to take 1 orange
for each person that came over to the United States when it
was being colonized to prevent scurvies and various other
ailments.

I don't know nothing about nothing, and I don't have a clue
about those hydrangeas, just passing along some information.

--
Jim Carlock
http://www.microcosmotalk.com/
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wrote in message
...
I have three flowering (not yet actually flowering) hydrangeas in
containers in my courtyard, which is generally very shady and
sheltered. For the last three years, the hydrangeas seemed to be
growing pretty well, though the one which got the most sun grows less
than those which get more sun. But this summer, about a month ago,
the leaves of the sunniest one started to turn brown, and then the
middle one, too, and now all three have brown leaves. At first I
thought it might be sunburn, but the conditions haven't changed since
they were planted, so why just now? There has been root rot in other
containers in my courtyard, but these leaves are not wilting, just
turning brown.