remove all the black spot leaves before spraying them? On some of my
bushes there wouldn't be much left and I wondered if that would
interfere with the stem development

Rose B

wrote :
remove all the black spot leaves before spraying them? On some of my
bushes there wouldn't be much left and I wondered if that would
interfere with the stem development

I've read claims that so long as the leaves are still green enough to
function,
it just cripples the plant further to remove them. They're lost anyway once
black spot has taken hold. Try to kill the spores and halt the progress
with
the spray, and remove the fallen leaves.

Opinions? I vaguely recall having read that what I wrote above was
confirmed by scientific studies.

Now, for stems invaded by black spot, maybe removal would be the thing
to do...

Mark., been spraying with peroxide a lot to kill spores; seems to help
so far but I can't say for sure

In article , Mark. Gooley
wrote:

wrote :
remove all the black spot leaves before spraying them? On some of my
bushes there wouldn't be much left and I wondered if that would
interfere with the stem development

I've read claims that so long as the leaves are still green enough to
function, it just cripples the plant further to remove them. They're
lost anyway once black spot has taken hold. Try to kill the spores
and halt the progress with the spray, and remove the fallen leaves.

Opinions? I vaguely recall having read that what I wrote above was
confirmed by scientific studies.

Yes, the non-stripping was the opinion of a Texas plant pathologist
back in the late 70's, from what I read he

http://www.rosekinggardens.com/faqs/blackspot.htm

Makes sense.

In article , Cass says...

In article , Mark. Gooley
wrote:

wrote :
remove all the black spot leaves before spraying them? On some of my
bushes there wouldn't be much left and I wondered if that would
interfere with the stem development

I've read claims that so long as the leaves are still green enough to
function, it just cripples the plant further to remove them. They're
lost anyway once black spot has taken hold. Try to kill the spores
and halt the progress with the spray, and remove the fallen leaves.

Opinions? I vaguely recall having read that what I wrote above was
confirmed by scientific studies.

Yes, the non-stripping was the opinion of a Texas plant pathologist
back in the late 70's, from what I read he

http://www.rosekinggardens.com/faqs/blackspot.htm

Makes sense.

I was amazed by what he said about removing the fallen leaves that have BS on
them:

"Fallen leaves. Dr. Lyle concluded, "Fallen leaves on the ground or top of the
mulch are not a source of carryover of the disease, even though this is a
frequent belief. As soon as the diseased leaves fall and start to rot, the
blackspot disease also decays. There is no need for removing the mulch that
remains from season to season. Just add more to it as needed."

According to the way I read it, no real need to remove the leaves from the
ground.

elfa

Though this could be true
it is not entirely my experience.
Also do you think this might
be 'dated' research being from
the 1970's.

I do agree that the spores actually
hide in the stems and the attack leaves
once rain begins.

After infected leaf removal it is
kinda important to spray the stems
with some spore killer. I've had great
results with the cornell formula in spring.

Dormant spray in winter helps too.

recently I've had great results w/ liquid manzate
when I've sprayed manzate w/ clearys 3336 and
taken care to soak the canes even without removing
leaves disease is stopped in its tracks.

I still strip the first 18" of large rose bushes
though. Has been very very effective in disease control.


--
Theo in Zone 5
Kansas City




"Fallen leaves. Dr. Lyle concluded, "Fallen leaves on the ground or top of
the
mulch are not a source of carryover of the disease, even though this is a
frequent belief. As soon as the diseased leaves fall and start to rot, the
blackspot disease also decays. There is no need for removing the mulch
that
remains from season to season. Just add more to it as needed."

According to the way I read it, no real need to remove the leaves from the
ground.

elfa

In article , elfa
wrote:

In article , Cass says...

In article , Mark. Gooley
wrote:

wrote :
remove all the black spot leaves before spraying them? On some of my
bushes there wouldn't be much left and I wondered if that would
interfere with the stem development

I've read claims that so long as the leaves are still green enough to
function, it just cripples the plant further to remove them. They're
lost anyway once black spot has taken hold. Try to kill the spores
and halt the progress with the spray, and remove the fallen leaves.

Opinions? I vaguely recall having read that what I wrote above was
confirmed by scientific studies.

Yes, the non-stripping was the opinion of a Texas plant pathologist
back in the late 70's, from what I read he

http://www.rosekinggardens.com/faqs/blackspot.htm

Makes sense.

I was amazed by what he said about removing the fallen leaves that have BS on
them:

"Fallen leaves. Dr. Lyle concluded, "Fallen leaves on the ground or top of the
mulch are not a source of carryover of the disease, even though this is a
frequent belief. As soon as the diseased leaves fall and start to rot, the
blackspot disease also decays. There is no need for removing the mulch that
remains from season to season. Just add more to it as needed."

According to the way I read it, no real need to remove the leaves from the
ground.

Maybe not for blackspot - that I can't address, as I have little here -
but it is not true of rust, which does overwinter. So I think the broad
statement is not correct, *if* it is correct for blackspot. I didn't
quote the article as an advocate, btw. I just was reporting the
research, that it is old, and the source.

Everyone in the past 300 years has recommended cleaning up under roses.
The persistence of spores is the primary reason. And blackspot isn't
the only fungus - anthracnose, rust, powdery mildew, cercospora,
botrytis, brown canker, brand canker and other things that go bump in
the night.

In Cass wrote:
Everyone in the past 300 years has recommended cleaning up under roses.
The persistence of spores is the primary reason. And blackspot isn't
the only fungus - anthracnose, rust, powdery mildew, cercospora,
botrytis, brown canker, brand canker and other things that go bump in
the night.

Where possible I follow the conventional wisdom. One year I didn't, and
the difference was too big to dismiss or attribute to something else.

I wouldn't go see Dr Lyle if I had a cold :-)

In article .com.au,
Daniel Hanna wrote:

In Cass wrote:
Everyone in the past 300 years has recommended cleaning up under roses.
The persistence of spores is the primary reason. And blackspot isn't
the only fungus - anthracnose, rust, powdery mildew, cercospora,
botrytis, brown canker, brand canker and other things that go bump in
the night.

Where possible I follow the conventional wisdom. One year I didn't, and
the difference was too big to dismiss or attribute to something else.

I wouldn't go see Dr Lyle if I had a cold :-)

LOL. I'm with you.