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