just_me, it's hard to say what might have happened without some more information or pictures.

Are they re-leafing now? If so, don't worry about it. If not, well, wait awhile and then repost with more information about the roses and maybe some pictures.

Good luck!

Probably blackspot. My ZD has some of it now and with the heat the leaves drop pretty fast. Can you see the leaves on the ground? Are they yellow with some spots? Then it's likely blackspot. The blackspot pressure seems very high this year.

I'll second the Blackspot. Zephy is very prone to it and drops her leaves faster than a speeding bullet. I moved mine because I had her on my front arbor and she was so unsightly most of the time. She is now in a place where she gets only afternoon sun and she seems to be doing much better. Go figure.

I have a climbing Rainbow's End that does that in the Spring when it gets blackspot - this Spring it dropped all of its leaves when it was in full bloom - the flowers were not affected - it looked hilarious, with all of those lovely blossoms on a naked plant. After the blooms faded, I cut them all off, and now it has leafed out again, and looks fine. It is the only rose I have that does this.

Jackie

I vote for BS as well. I have Climbing American Beauty. For the first few year it got BS real bad and I had to spray it. Now that I have had it for about 7 yrs, I noticed especially this year even without regular spraying it is finally staying pretty clean. I am trying to go no-spray so it was sprayed early spring and that was it.

Liz

well, yeah, blackspot; if so, it should releaf.

but what about drainage problems? I'd wonder about that too, esp if it's been really wet. Wouldn't that cause leaves to yellow and fall off and subsequently probably NOT releaf?

Maybe I'm nuts, but that's what I was getting at.

Here is a link that might be useful: drainage prob with roses

I tried to post this yesterday, but it didn't take?

When there's total leaf drop, you can't omit the possibility of Downey Mildew. Usually with Black Spot, the older leaves drop but the newer leaves remain. It just takes the newer leaves a bit longer to get BS sick enough for them to drop.

Right now, the heat should suppress either disease. But you might want to be ready this fall to contact your county extension agent and for he or she to have someone at state up to snuff on DM identification, just in case.

DM is a lot more serious than BS.

Good point, Downey Mildew can be another possibility.
However, here BS often defoliates plants completely. Sick plants can get stunted by BS and not grow a lot of new leaves.
Olga

I am the original poster of this message. I haven't had a chance to take photos yet but I will do that soon. I remember when I looked on the ground around the base of my roses, it was as if the leaves had just disintegrated. The leaves weren't even in big enough pieces to see what happened to them.

As I said before, I had been distracted with houseguests and other things for awhile so I didn't notice this problem until it was way too late to look at the leaves and try to diagnose what happened. The leaves just seemed to have ended up on the ground as a sawdust-like material.

I will look tonight to see if there are any new signs of leaves. They have been without leaves for a long time now.

I did think of one thing that I did differently this spring. In addition to an extremely steamy, humid and wet spring and early summer, I put down a heavy layer of shredded wood mulch from Southern States. Not sure exactly what it was comprised of. I usually use a thin layer of pine chips.

I had this problem with NurMahal last year---but it recovered nicely with lots of blooms this year----

ZD can be prone to BS but I have found the regrowth is quick and pretty----

Florence