Lyn, is it the temperature or the lack of humidity that keeps blackspot from living? It seems to thrive in our hot times, but that always means humid too in this area.
We gardeners are as tenacious as weeds aren't we! LOL No matter the challenges nature provides, we're going to grow something, some how, some way....
"...and don't think the garden loses its ecstasy in winter. It's quiet, but the roots are down there riotous." Rumi