I thought I read you can use Palm fertilizer on knockout roses. True?
Fertilizing any plant or shrub comes down to what it needs most for optimum performance. If the fertilizer used is too high in Nitrogen it will cause increased foliage production and limit the bloom production to few or no blooms. Some fertilizers also contain a pH altering compound to help adjust the pH to one that is more suitable for the desired plant. I do not recommend using a fertilizer listed for a certain kind of plant for another unless it has a group of plants listing upon it. Such as one I used called Gro-Rich Rose and Perennial Food. In such a case it is listed and has application directions for rosebushes and perennial plants.