Rose plants insects

[Gardenhelp]

 

 

 

Hi Team,

My rose plant show above has the leaves and stems turn black /brown / yellow and rust. I use  Yates scale insecticide but it does not seem to work. Is there anything which I can do to prevent the problem from reoccurring?

 The rose shown above, is a fairly tall shrub. I will like to prune it to a round short bush . How best can I do this? Are you able to advise me on these problems?

Thank you

Kind regards

Gardenhelp

garden help