Posted: 10/08/2015 at 21:15
Jo, there are now special feeds just for roses, clematis, tomatoes, leafy plants and so on. The differences are in the ratios of levels of nitrogen, potassium and phosphorus.
N - nitrogen - promotes strong stem and foliage growth
P - phosphorous - roots
K - potassium - plant health, disease resistance, flowers and fruits
All should contain varying levels of other trace elements such as copper, iron and magnesium and so on. Try and get to know these and you'll know what to feed your roses. Failing that, check the RHS advice on feeding roses.