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roserich

total defoliation and new growth

I've been faithfully picking off all yellowing leaves and those that get spotty. I've noticed that on some of my roses this pretty much completely defoliates them. With a couple of deep waterings they rebound and refoliate.
Is that pretty common with modern roses?
My gallicas looked so horrible with PM and rust that I just whacked them back and watered well. Now they have healthy green PM growth. Perhaps I am just too warm and humid for gallicas?
Susan

Comments (10)

  • bart_2010
    10 years ago

    This is happening to some of my roses, too.I'm not sure what to make of it. The weather has been of the sort that encourages b-spot, and I did not get around to doing a copper spray. The older canes which have now finished flowering have completely defoliated,but healthy new ones are coming out. I'm wondering: should I prune out the old, defoliated canes? Could it be that these are survivors from the last two years of pretty severe drought,and are just too weak to go on? bart

  • catsrose
    10 years ago

    Neither poorbutroserich nor bart posts where you are or what zone, so its pointless to comment on your conditions. However, rule of thumb, the roses will refoliate, so just leave them alone.

  • michaelg
    10 years ago

    PBRR-- Rose rust in Nashville would be a rare occurrence owing to freaky spring weather. I have never seen it in Asheville, which has a more suitable climate than Nashville, but only in a town at 2800 elevation in western NC. Severe chronic mildew would be unusual in Nashville, and there are many easy and safe ways to control PM. Both these diseases will clear up with summer weather, and you will probably never see rose rust again. I think you can grow gallicas successfully and with few problems. The only drawback is that hot weather in late May-early June can shorten the blooming season for once-bloomers.

  • mad_gallica (z5 Eastern NY)
    10 years ago

    Gallicas can get something that looks like rust, particularly to easterners who often never get to see the real thing. It's a brown necrosis around the leaf edges that behaves like a nutrient deficiency as much as anything. Some varieties are particularly prone to it. The worst offender in my garden is Mecene, which was banished to the most inhospitable place here because of it.

    The defoliating/refoliating cycle is how BS susceptible roses behave in humid places. The new leaves will spot in about a month, and the whole thing will start all over again. Some roses are strong enough to handle it, some aren't.

  • mad_gallica (z5 Eastern NY)
    10 years ago

    So you are talking about something that looked like maple tar spot? Not something I've run into. From a quick trip around Google, I do wonder if it IS maple tar spot. It seems to be able to exist on a surprisingly wide variety of species, though I didn't see any specific reference to roses.

  • Poorbutroserich Susan Nashville
    Original Author
    10 years ago

    Sorry Catspa I thought I was enough of a regular here for folks to know my Zone. I'm in Nashville, Tn. Thank you Michael for remembering and answering.
    Thanks to Mad too.
    It was a freaky wet spring and then the heat came on...but they looked awful.
    I will be patient! I'm on the three year plan anyway. Thanks.
    Michael, my Monarda and Phlox mildew. Is that ocmpletely different from mildew on roses?
    Susan

  • catsrose
    10 years ago

    Susan, I'm Catsrose, not Catspa. We are two different people. Thank you for updating your info.

  • meredith_e Z7b, Piedmont of NC, 1000' elevation
    10 years ago

    I don't pull off spotty (from BS) leaves. If they are yellow and fall off to the touch, I knock those off, but I figure that green leaves are still working for the plant. There is enough BS in my garden that I don't think culling spotty leaves will help regarding risk of infection.

    I have a lot of roses that do well but have various levels of spotty foliage. The infection only goes so far sometimes, apparently (just an observation, not something I've researched).

    I definitely have a few roses whose foliage yellows and actually drops, so I'm familiar with that, but it might not happen to all spotty leaves, depending on your conditions compared to mine, etc, of course :) MIP has pretty new leaves at the moment, after dropping every leaf she had this year.

    I do cut out ugly parts of canes if they look to have anything more than BS on them. But we get cankers/die back so easily in spring that I just don't risk anything weird cane-spreading. I don't cut green canes with BS spots, but if they are going yellow from it, I cut below the yellow. Yellowing canes are usually toast sooner or later, in my experience.

  • michaelg
    10 years ago

    Susan, mildew on your other plants is a different species that does not affect roses, nor does rose mildew affect them.

    The rose species affects apples, but apparently they are different races that rarely cross-infect.