By Jointhegreen
United Kingdom 
I live about a mile away from the coast in Hastings, East Sussex and planted 2 climbing roses in the ground last summer. They are growing up a wide area of trellis, planted 4 feet apart, get the sun until midday and have the neighbours fence behind them with a 2 foot airgap. Both were doing very well until early July when they both developed black spot, I have taken off all affected foliage and sprayed them. Do they have any chance do you think? This is my first big experiment with roses, and about 2 thirds of the plants are infected before I realised there was a problem.
17 Jul, 2017
Answers
Roseclear Ultra its called now, and I'm afraid I agree with the previous answer, it is necessary to spray preventatively from leaf break through to the end of the growing season, as often as it says on the bottle, which used to be fortnightly, but may have changed since the product's reformulation. Be sure not to leave any dead rose leaves on the ground over winter.
17 Jul, 2017
They will overcome this problem and the infected leaves will eventually fall. I would gather all the dead leaves and continue to spray at the intervals as described on the bottle (Roseclear). Next year, you need to begin a spraying programme as soon as there is a reasonable amount of leaf burst. I would also spray the trellis as the blackspot spores can remain on it also.
17 Jul, 2017