What is the best organic fertilizer?
I really do not think there is a best organic rose fertilizer. There are several on the market that do a fantastic job of both building a great soils home for our roses and helping bloom production to be at its best, thus a happy, hardy rosebush. Here is a list of some I either have used or currently use in a rotational basis for my rosebushes.
1, Gro-Rich Rose and Perennial Food - Organic based using dried poultry waste.
2. Mile Hi Rose Food - Locally manufactured here in Colorado USA. Top notch organic fertilizer.
3. Rose-tone by Epsoma - Very good.
4. Dr. Earth Rose and Flower Fertilizer
5. Jobes Organics Rose and Flower Food
6. Mills Magic Rose Mix
There is at least one organic rose food on the market that says it is specifically for Knockout roses. There is no real difference between the Knockout roses fertilizers and other rose fertilizers. It is just a marketing thing to try to capitalize on the popularity of the Knockout roses. Other rose fertilizers will work just fine on the Knockout roses and the Knockout roses fertilizer will work fine with other roses. Just watch what you are paying for "specialty" fertilizers! I also like to give my rosebushes a cup of Kelp Meal twice per season and a cup of Alfalfa Meal per season. Do not use rabbit food pellets to feed rosebushes due to the alfalfa content of the food. It has a considerable amount of salt in it that can cause big problems for the soils and the rosebushes.