Nitrogen is an important element for roses as it stimulates the growth of the leaves and stems while increasing the overall size of the plant.
A shortage of nitrogen in the soil will produce small young leaves that are pale green in colour, sometimes developing red spots. This condition will cause leaves to drop early with stunted, weak growth in the stems.
Apply Trace Elements and feed regularly. Click here for more information of feeding.
Alternatively you can buy a pack of Trace Elements from your local garden supply shop. It is chrystals that you can mix into water and pour onto the ground around the affected plant. This is to be used once only in most gardens but may need repeating in well used soils.
Any treatment will take a couple of weeks for you to see signs of improvement in the new growth.
Important: signs and symptoms will vary significantly between varieties, even within similar categories. The information provided here is a basic summery of the most common affects and will not always be applicable to all rose varieties.