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We inhertied quite a lot of various types of roses in our garden, scattered around all over. noticed on quite a few of them all the leaves have dark spots or blotches on them. What is this and how bad isi it?

Black spot is the problem, and it needs spraying with a fungicide.  When the leaves have dropped, in Autumn, collect them up and burn, in order to try to avoid reinfestaion next year.  Also spray the ground with the fungicide..

How bad is it?  It is something to try to eradicate, as it doing the plant (rose) no favours.

It is a very common rose problem, and needs to be workked at to get rid of.

valmarg

thanks, does it contaminate anything else or just restricted to roses?

As far as I know, it is only a rose problem but someone else may correct me here? It can be a major problem causing mass leaf drop.

Black spot is common on roses, avoid watering your roses when it is sunny. One way of controlling black spot quite effectively is by using Rose Clear - pesticide and fungicide, but you may prefer an organic way of dealing with it. Some people spray the leaves with a 1:1 mixture of skimmed milk and water, but I cannot verify how effective this method is. Its supposed to change the pH of the leaves, to discourage black spot growth. Another way is to use a sulphur spray and this method is supposed to be organic. I am trying that this year as I am growing veggies near my roses for the first time, and do not want to contaminate my veggies, tomatoes etc. with any fungicide/pesticide chemicals.

Good luck.

vegw