Roses are heavy feeders and make large demands on the soil. If one or more of the necessary elements is deficient in the soil, we begin to see the signs of hunger. If a rose does not have adequate nutrients it will not have the ability to successfully fight off diseases and pests and will become susceptible to damage. Therefore it is very important that roses are fed regularly.
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.