During hot, dry weather in summer roses can be plagued by red spiders; and during frequent rainy or humid weather, they are more susceptible to fungal infections like rust, powdery mildew and black spot, so do some preventative spraying to stop infections from occurring; in very humid regions downy mildew may also become a problem.
Want glorious roses in autumn?
Give your roses a little tender loving care in February and you will be rewarded with a breath-taking flush of blooms in autumn. As the weather cools down your rose bushes will produce long lasting blooms of the most intense colours. If you have not done so yet, replenish the mulch around the roots and water deeply and regularly every two to three days. Do not fertilise in February, but towards the end of the month feed with fertiliser that is high in both nitrogen and potassium like 5:1:5 or 3:1:5.