Michael: My experience with large & glossy foliage: Initially I thought they need more water, but they actually prefer alkaline ... if it's too much acidic rain, hard minerals get leached out, and leaves wilt easily. My Meilland "Sweet Promise 2007" has the most glossy foliage, and I constantly have to lime that to neutralize acidic rain. David Austin rose Evelyn also has large & glossy foliage, I put the outflow of my rain-barrel, dumping tons of rain on that one. Then it got up to 70 F, and it WILTED in partial shade !! So I topped that with ALKALINE pea gravel (pH 9) for minerals .. leaves became thicker, and no more wilting.

Same with Austin rose Wise Portia (prefer alkaline). I put the rain-barrel overflow on that one, it received tons of rain, then it also wilted in partial shade. So I gave it Azomite (alkaline-mineral-powder, pH 9) and it stopped wilting. Rain leaches out calcium (makes leaves thicker), and magnesium (makes leaves shiny). Roses with glossy foliage have a higher need for alkaline minerals. I tested dunking cut blooms in different combo with ACIDIC rain-water (pH 4.5 in Chicagoland): with dolomitic lime, with red-lava, with Azomite .. and the cut blooms in Azomite solution last longest in the vase. Azomite is a fine-powderm & easily absorbed by the stems. Sold cheap on Amazon, $10 for a large bag. After testing Azomite on many roses, I prefer that over lime, since Azomite has many trace elements, besides calcium & magnesium.