In article , Susan Solomon
wrote:

Greetings, fellow rose-lovers
I have a problem and a question. This year I was late in pruning.
(2-15-03 ... very late here in Santa Barbara, where it never freezes, and
where our city rose garden is pruned on 1-15) And unfortunately, I didn't
dormant-spray immediately after I pruned the roses. I did defoliate all of
them after pruning, and raked up the leaves. Well, now my beauties are
bursting with vigorous new leafy growth and buds ... and rust!!!

Is it too late to spray dormant oil? What is my best alternative? The new
growth is very tender; I am afraid that anything I spray will burn the
leaves.

One alternative that I thought of would be to go ahead and spray with
dormant oil, then cover the plants with 50 percent shadecloth for a few
days. Would that keep them from burning? Any other ideas or suggestions?

First, considering how hot it is, maybe the rust will die off by
itself. Second, there is a lighter weight horticultural oil intended
for warmer weather use. Look for Ultra fine. I've never had much luck
with oil sprays on foliage, to tell the truth. I've never done it for
long, but what I did do, didn't seem to work. Third, if you are willing
to spray, maybe you should consider a fungicide that is really
effective for rust. Take a look at www.rosecare.com or Rosemania. My
personal approach is to put up with it or yank them.