You'll have better luck posting your question in the general Roses Forum, link below. This one if for questions on propagation.

I can say that here in NJ, Lagerfeld needs to be treated regularly with a fungicide to prevent blackspot. Mine grows OK, it may be better with more heat, but someone closer to you would be able to give better info.

Here is a link that might be useful: Roses Forum

Thanks Diane,
I meant to post on regular rose forum. Must have gotten in a hurry.
I also posted on Texas forum, but no responses yet.