Lavenderlace: The ones with blackspot reputation: Heirloom, Angel Face, Barbra Streisand do best in FAST draining alkaline soil. My Heirloom (grafted on Dr.Huey) is 100% healthy in a fast-draining loamy mix of clay & humus (next to the tree), so it never get water-logged, even if we get tons of rain. I spent 1 hour digging that hole down past 2 feet, to make sure water can drain fast.

If there's a bed of rocks, or dense clay at the bottom to block drainage, the BS-fest roses won't like it. I used husband's electrical drill to punch at least a dozen holes in the pot for Barbra Streisand, so far zero blackspot in this week-long rain. In contrast, Blue girl (grafted-on-Dr.Huey) needs more moisture .. I thought it died this winter, but after tons of rain, it sprout healthy canes. Waterhogs like Bluegirl prefer a bed of dense clay at bottom to retain water, same with French Meilland, or Romantica roses.

There's a spot in my garden with thick & sticky dense clay at bottom. I planted a Knock-out (grafted on Dr.Huey) and it HATED that, lost lowest leaves due to poor-drainage. So I planted OWN-ROOT French Meilland rose, Sweet Promise (with dark green & glossy foliage) .. it loves that dense clay & wet spot, leaves became so shiny .. but I had to keep the pH near 8. Anything standing in acidic rain water will break out in blackspot, so I constantly limed that wet spot to keep Sweet Promise healthy. I did a bunch of experiments in the vase with cut flowers: Pink Peace leaves broke out in blackspot if soaked in a vase of acidic rain water for a few days, but if I put pea-gravel or use my alkaline tap water (pH 9), leaves stay healthy, even if the stems are in the vase for a few days.