I'm at my wits end, try as I might, I have been unable to defeat blackspot.
Year after year I search for the first signs of leaf marking that signals
the onslaught. I spray religiously, chemicals, organic solutions nothing
seems to work. I love the beauty of my roses, but it always seems to be
short lived. The hot humid climate here in W. Central Illinois seems
perfect conditions for blackspot. I have cleaned and disposed of infected
foliage but sooner or later it returns. I'm close to giving in to the
inevitable.

Art Lindquist wrote:
> I'm at my wits end, try as I might, I have been unable to defeat blackspot.
> Year after year I search for the first signs of leaf marking that signals
> the onslaught. I spray religiously, chemicals, organic solutions nothing
> seems to work. I love the beauty of my roses, but it always seems to be
> short lived. The hot humid climate here in W. Central Illinois seems
> perfect conditions for blackspot. I have cleaned and disposed of infected
> foliage but sooner or later it returns. I'm close to giving in to the
> inevitable.

If you are waiting for signs of blackspot before you start spraying,
that may be part of your problem. Particularly if you KNOW your roses
will get blackspot, you'd probably do much better to start spraying
before the first sign of the fungus shows up. The idea is to prevent
it. There is no "cure", per se. Fungicides can keep it from spreading
but nothing will make black leaves turn green again.

I've had good results from Orthenex concentrate (an Ortho brand
containing 0.75% Fenbutatin Oxide, 3.25% Triforine, and 4.0% Acephate).
The Triforine is the fungicidal ingredient. Orthenex is a systemic
that kills insects (listed for aphids, budworms, leafminers, flower
thrips, lacebugs, leafhoppers, spittlebugs, fuchsia mite, and
two-spotted spider mite), and prevents black spot, powdery mildew, and
rust. It carries a warning that it can cause irreversible eye damage so
you really should wear eye protection at the very least. I wear elbow
length rubber gloves, goggles and a respirator and I shower immediately
after spraying.

The other thing to know is that some roses are considerably less
susceptible to black spot than others. I made the mistake of trying to
grow Rosa foetida (Austrian Briar). I've never seen a rose get hit so
hard by fungus. On the other hand, 'Pat Austin' and 'Mayflower' (both
David Austin roses) are almost completely free of black spot. Other
roses fall between these two extremes. Naturally, your mileage may
vary. You might try to find rose gardens in your area, find out what
grows well and give those varieties a try. Roses that do well in
Albuquerque or Washington, DC may not do well in Chicago, and visa versa.

--
Henry

n Tue, 24 May 2005 20:04:55 -0400, in rec.gardens.roses you wrote:

>Art Lindquist wrote:
>> I'm at my wits end, try as I might, I have been unable to defeat blackspot.
>> Year after year I search for the first signs of leaf marking that signals
>> the onslaught. I spray religiously, chemicals, organic solutions nothing
>> seems to work. I love the beauty of my roses, but it always seems to be
>> short lived. The hot humid climate here in W. Central Illinois seems
>> perfect conditions for blackspot. I have cleaned and disposed of infected
>> foliage but sooner or later it returns. I'm close to giving in to the
>> inevitable.
>
>If you are waiting for signs of blackspot before you start spraying,
>that may be part of your problem. Particularly if you KNOW your roses
>will get blackspot, you'd probably do much better to start spraying
>before the first sign of the fungus shows up. The idea is to prevent
>it. There is no "cure", per se. Fungicides can keep it from spreading
>but nothing will make black leaves turn green again.
>
>I've had good results from Orthenex concentrate (an Ortho brand
>containing 0.75% Fenbutatin Oxide, 3.25% Triforine, and 4.0% Acephate).
> The Triforine is the fungicidal ingredient. Orthenex is a systemic
>that kills insects (listed for aphids, budworms, leafminers, flower
>thrips, lacebugs, leafhoppers, spittlebugs, fuchsia mite, and
>two-spotted spider mite), and prevents black spot, powdery mildew, and
>rust. It carries a warning that it can cause irreversible eye damage so
>you really should wear eye protection at the very least. I wear elbow
>length rubber gloves, goggles and a respirator and I shower immediately
>after spraying.
>
>The other thing to know is that some roses are considerably less
>susceptible to black spot than others. I made the mistake of trying to
>grow Rosa foetida (Austrian Briar). I've never seen a rose get hit so
>hard by fungus. On the other hand, 'Pat Austin' and 'Mayflower' (both
>David Austin roses) are almost completely free of black spot. Other
>roses fall between these two extremes. Naturally, your mileage may
>vary. You might try to find rose gardens in your area, find out what
>grows well and give those varieties a try. Roses that do well in
>Albuquerque or Washington, DC may not do well in Chicago, and visa versa.

All good advice.

If you have a serious case of blackspot, know that the spores are
going to overwinter. Therefore, you need to spray everything,
including the ground, with dormant spray once the plants go completely
dormant. In your case, that would probably be anytime after
Thanksgiving.

Ortho also makes Funginex, which has been renamed "Rose's Pride". It
is also quite toxic to the eyes, so protect them.

dave weil wrote:
> Ortho also makes Funginex, which has been renamed "Rose's Pride". It
> is also quite toxic to the eyes, so protect them.

I forgot about that. Funginex (Rose Pride) is the same fungicide as in
Orthenex without the added insecticides (and in twice the strength).
Since that's where the danger to the eyes comes from, the same cautions
apply. If you don't have insect problems, you are better off using just
the fungicide. I have serious insect issues so prefer both.

--
Henry