Blackspot on Roses

[johntheplamf]

What can i do to cure this please?

[woofgang]

Black spot sits within the plant rather than on top of it and overwinters in crevices on the bark. At this time of year to be honest, there is not a lot that you can do. Remove all affected parts from the plant, dispose of them outside of your garden (used to say burn but that's not PC now) and disinfect the secateurs with jeyes fluid. Feed the plant well to assist it to recover You can buy sprays and they may help. As I understand it the best treatment is to spray with armillatox when the plant is dormant (instructions on the bottle) Keep the area around the plant clear of dropped leaves all year as these harbour the disease and try to get good air circulation to reduce humidity which nurtures the black spot. So grow the plant in airy conditions, not hemmed in with other plants, prune it to keep the centre of the bush open. That's the traditional advice. Of course you can always choose black spot resistant varieties but if you plant them where the old infected rose was, it might still get it so plant something else where the rose was and plant the new rose somewhere else.

[woofgang]

there are also loads of websites like this

[woofgang]

and here's one that talks english!! blackspot

[johntheplamf]

Thanks very much Woofgang, You truly are the blackspot guru.

[woofgang]

yup, sad isn't it!!

[johntheplamf]

Sad, but very helpful;-)

[Clanad]

While generally agreeing with woofgang, I'd add that the spores of the Black Spot fungus are best controlled, if not eliminated, in the early spring before plants begin to show life.  A spray that I've used for years, called dormant spray or lime sulphur , (same product, different name) does the job very well.  Although foul smelling (it is sulphur) it is mixed with water and sprayed on the ground and the bottom of the plant.  It does a very effective job.  Remember, the fungus spores actually move up the plant, infecting lower leaves and progressing.  It can defoliate a plant in just two or three days under the right circumstances. If the fungus is noted once the plant begins growth, I've had very good results from a product processed from chrystanthimum seeds called Neem Oil.  It not only controls the fungus, but makes the leaves nice and shiny (controls spider mites as well).  Thoroughly drench the plant with prepared spray, (top and bottom of leaves) once each 4 or 5 days until no more black spots or yellowed leaves are noticed.  Be sure, as woofgang states, to thoroughly clean the plant area of any leaves or debris and use lots of mulch... Good Luck!