Four more problems that affect roses
Look out for orange or black pustules on leaves and stems. Most of the modern roses are resistant to rust.
This fungal disease tends to be worse in high humidity and in plants where air movement is poor.
Aphids suck sap from leaves and stems and secrete sticky honeydew, which encourages the growth of sooty moulds.
The caterpillars of the rose sawfly will eat the leaves of roses, sometimes completely defoliating a plant.