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ROSES : Black Spot
Looks as if I am finally going to have to admit defeat. Anyone succeeded in overcoming this pest?
Some seven years back, decided to cover a North-facing wall with climbing roses: mostly Iceberg and Danse de Feu.
Most years, they had been the garden's star performer, displaying a profusion of blooms from early Summer to around Christmas time. No more so, due to Black Spot.
Removal of diseased growth and foliage has left them so leggy, that they are no-longer effectively screening the wall, and blooms, much reduced are now restricted to being too high up to appreciate.
Have tried copper based solutions, and Beyer's 'Fungus Fighter Plus'. They work, temporarily that is, until we get one of the all too frequent wet spells, when the Black Spot inevitably advances again. It is widespread in the locality. Even the local authority's plants in the park are heavily Black Spot infested.
So, it is either replace them, taking precautions against re-planting disease. (What used to be called Rose-Sick) Or, at risk of killing the plant severe prune to see if it will produce new shoots for training. Thereafter, would have to espalier them, rather than having them scramble to cover the wall, so that all parts are low enough and exposed for spraying, and immediate removal at first sign of any infected leaves.
Replied: 31st Oct 2017 at 15:14