Roses get black spot because air quality is good Back in the days when everyone had coal fires and the air was sulphurous and smoggy and gave everyone bad chests, the roses didn't get black spot because the sulphur helped kill the spores that cause it.
Some roses are more resistant to black spot than others, so choose those if you can. When pruning keep the centre of the bush open to allow for good air flow. If you water your roses, water the soil not the leaves.
Don't over-fertilise the roses - grow them 'hard' using slow release fertiliser such as Fish Blood and Bone, as high nitrogen fertilisers will give rise to soft lush growth which will be more susceptible to infection - and every autumn when the leaves fall, rake them up and burn them.
I spray mine with sodium bicarb and washing up liquid weekly and after it rains. This greatly reduced the blackspot in my roses and is cheap. The bicarb makes the surface alkaline which the black spot doesn't like. The washing up liquid makes it stick.
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Roses get black spot because air quality is good
Back in the days when everyone had coal fires and the air was sulphurous and smoggy and gave everyone bad chests, the roses didn't get black spot because the sulphur helped kill the spores that cause it.
Some roses are more resistant to black spot than others, so choose those if you can. When pruning keep the centre of the bush open to allow for good air flow. If you water your roses, water the soil not the leaves.
Don't over-fertilise the roses - grow them 'hard' using slow release fertiliser such as Fish Blood and Bone, as high nitrogen fertilisers will give rise to soft lush growth which will be more susceptible to infection - and every autumn when the leaves fall, rake them up and burn them.
There are also organic sulphur-based sprays that may help prevent infection, but the trick is to apply the sulphur before the spores have landed on the leaves. See here http://www.rosemagazine.com/articles02/pages/blackspot.asp
I hope that's helpful
I find that roses that are well fed and watered are more resistant to disease, but some sorts of rose always seem to get black spot and others don't.
I spray mine with sodium bicarb and washing up liquid weekly and after it rains. This greatly reduced the blackspot in my roses and is cheap. The bicarb makes the surface alkaline which the black spot doesn't like. The washing up liquid makes it stick.
Thanks guys for your response, I will endeavour to correct it. Much appreciated