hi sept, do you smoke or do you know someone who does? either way ask them for the contents of the ashtrays, throw away the butts but keep the ash, the ash is full of nitrates and is pretty good for a wide variety of plants, just sprinkle it around the rose bush base, you should still "feed" and water them per instructed, this just gives it that last kick in the butt to encourage growth, works wonders with tomatoes has well