I planted GC this past March and mine is planted around my deck similar to have yours planted and it has had BS, I am in zone 8 in east Texas Ina very hot and humid climate so BS is a problem for me, but the amount of BS on GC has been minimal and I have been able to keep it under control by keeping the offending leaves picked off, other than that it has been very healthy and growing like crazy and has put off 2 very long canes that I am training to go up my deck. I do not spray either. On the other hand my red Don Juan has had awful BS and is now almost defoliated where GC only had it on the very bottoms and still is bushy and full of leaves.

Mine is planted stand alone and it does spot a lot so I don't think it's a location issue. I just think GC is black spot prone.

Seil-that's disappointing. I dug the bed significantly further out and added a stone border to keep the grass at a strict distance. I've been gloating a bit about how neat and tidy it looks now (and dry!) and telling myself it will make a big difference.

Oh well. I'll give it another year and see how it does. We've had a VERY cool, wet summer, not typical of our region. If it's no different next year I might switch it out for something tougher.

It's entirely possible GC is more black spot prone in your climate, but location is also a very likely part of the problem. If the other roses are not being attacked by slugs, it sounds as if the spot where GC is planted is more humid, which is what they like. Most insects, spider mites being an obvious exception, like "green house conditions". Warm, moist, still air suits them just fine which is why you very often find them in sheltered spots in a garden when the rest of the exposed areas aren't hosting them. It's also quite possible GC might suffer less from the black spot if you could reduce the humidity around it, which that lawn is definitely helping to provide. It's worth a try and it might help you diagnose the issue before you go planting another rose which may well experience the same issues simply because the location is unsuitable due to the higher humidity. Kim

As always, Kim generously shares expert advice. Just to say GC does well here & wondering what else may be going on in your garden. You don't mention the amount of sun your GC receives - could lack of sun exposure be a factor in GC's health & be keeping that area more damp? Do you have a mulch there holding too much water itself? How do you provide watering - sprinklers, drip, by hand, on what schedule & time of day or evening? If mechanically, could there be a malfunction? Any dips in the lawn or bed, gutters or downspouts slanting more moisture towards the rose? Is the area getting too much water? Is the rose itself getting too much or not enough? Any underplantings holding & releasing moisture? Any of these & more could impact the individual situation & immune resistance of your rose negatively, attracting bugs & disease.

Thinking over any contributing factors may help you rearrange & solve your puzzle. You might try a diluted seaweed spray foliar & root feeding to help boost CG's health. Consider temporarily removing any mulch & later replacing it with fresh, as it may be saturated with spores.

This garden is likely as humid as yours - seldom under 75% & usually closer to 95% in Summer, with frequent rainstorms. The CG here grows in a mixed perennial bed in an ESE exposure 8' out from the front porch. Gets 7-8 hours of sun from midmorning to late afternoon, in clay-based loam amended with gypsum & compost years ago & topped yearly with compost in Spring & oak leaf mulch in Fall. Compost doesn't touch the stems & mulch stops 8-10" inches from them until dormant in cold. Believe these conditions contribute to GC's good health these last 9 years with no antifungal treatments.

Troubleshooting is usually tough but necessary. Was your rose doing better till recently? If so, what's changed? Small changes often have big impacts. Put on your detective hat...

This post was edited by vasue on Fri, Jul 11, 14 at 12:59

Thanks for such thoughtful responses. This is the second year in the ground for GC and last summer it was spotty and disease prone as well. Glad someone pointed out that another rose might have the same problems in this spot, I wouldn't toss the rose before trying it in a different spot but I'd hate to keep rotating roses and seeing no improvement. I made some little changes and am hoping it starts to do better.

Though the spot gets a generous amount of sun (7-8 hrs) I think there were some factors making it more damp than the beds my other roses are in. The grass along the edge was very close and in some places directly underneath the canes. The pergola has a wisteria growing over the top putting the rose, though itself in full sun, on the edge of damp shade. I edged the new, wider bed with stone and pea gravel. We'll see!