Black Spot

[tearinghair]

For the last few years I've sprayed the roses with a general anti-disease rose spray. The blooms have been fine, but it hasn't touched the black spot on the leaves. Is there anything in particular you would recommend? I'm not sure whether giving a specific brand name counts as advertising so might be removed, but I really do need something different. I wouldn't want to start making up a mixture from scratch.

[Sammy48]

I sprayed mine with Rose Clear last year, it did work but all the leaves on the roses dried up crinkly and fell off. Result one very bare rose bush.

[ubasses]

http://apps.rhs.org.uk/advicesearch/profile.aspx?pid=270

The above should be of some help, but despite clearing all the leaves at the end of the season and spraying I do not seem to be able to shift it.

[tearinghair]

Thanks Ubasses, I didn't know about burying the leaves, and I'll try to remember that in the autumn. I'll try the first product the RHS recommends and see how that goes, but I see they suggest alternating them all anyway. It must be a more widespread problem than I realised - thought it was just me being careless.

Sorry, Sammy48, I didn't mean to imply that your reply wasn't helpful; it certainly was, as I'd had exactly the same result with Rose Clear.

[Clanad]

It's still not to late (at lesthere in the western U.S. and I suspect your area) to clean out all debris from inside the dripline of your affected bushes. Once that's accomplished, find a chemical called "Dormant Oil"... it'll mix in a sprayer and then thorughly soak both the bush as well as the ground inside he dripline.

BTW, it's also called Horticulture Oil and also helps control thrips and spider mites... It'll also control powdery mildew, whci may be more common on other flowering plants.

Caution, while Dormant Oil isn't toxic it smells terrible since it's made from sulphur. Don't get any on your shoes!

Use it again early next spring before the roses start to bring on leaves...

[tearinghair]

Thanks, Clanad. I think I'll try the other solutions first; the roses are just underneath the window, the weather is improving, and i wouldn't want the smell of sulphur drifting through the house via an open window...but certainly if nothing else works.