Can anyone tell me the cure for blackspot?,I know that now is the time to remove it and dispose of it.I just dont know the cure.Any answers out there?
There is no cure as such. Rigurous hygeine is the only answer. If you really want to go chemical there are things that claim to get rid of it, but as it is a spore and is everywhere in the country, I suspect these are very short term 'cures'. If you are buying new roses then try to get ones which are resistant. As you said, now is the time to pick off the affected leaves, remove the top inch or so of soil under the roses, and mulch well with clean compost or whatever you like to use.
I agree, the best bet is to buy resistant varieties. I have a lovely 'Peace' but it gets devastated every year, regardless of what I do. Two resistant varieties planted just feet away are untouched. As long as the Peace continues to flower it's socks off I'll probably keep it even if it does look unsightly at times.
I thought it might of been a matter of over watering.
No, David, it's fungal. The spores are airborne. Once it's in situ, it can also be transmitted via the hands, secateurs, etc.
As Bookertoo says, there are sprays that claim to deal with black spot but they're only of use if sprayed preventively - that is, very early in the season, before the spores arrive. Once the spores have settled on the leaves and the symptoms are showing, there's no point spraying. All you can do is remove the affected leaves, destroy them, and keep the ground around the plants clear of any diseased plant material.
Thanks very much to you both for all of your advice. ( you can't get that at B&Q )