What I've learned is even with organic - liquid- granular ( etc...)fertilizer, they can burn easily with too much. Make sure u water super duper well before n after fertilizing. So in ground would be 1 cup ( if bush been in ground over 6 mo) and half that (1/2cup) if it's been in ground under 6 months. in pots. it would be half of that ( 1/2cup ) for a bush been in pot for over 6 months and (1/4 cup) for bush been in pot under 6 months monthly. These are recommendations I was told by Mr. Hardin who owns Hardins nursery here in Tampa Florida and he has 3-4 thousand roses in 5 gallon pots always huge, beautiful and flawless! ....BUT!.....we have super hot weather here! so if I where u, I would use even half of these recommendations and also make sure u figure in how big your pots are and how often u do water your roses bc if left to dry out after feeding they will burn fairly quickly with chemical fertilizers. I also learned to go lighter on the feed when weather is super hot bc of burning. So They say- the more u water your roses, the more often your able to feed them. So if you don't water often be gentle on the feed. I've burned many roses since I've started so from experience, it's always easier to add more later! It's far from easy to fix a burnt rose! If I where u , I would also read the labels and maybe dilute what the recommendations are and I do know that organic takes longer to break down n start working and doesn't burn as easily as the chemical fertilizer however, chemical fertilizers give u faster results. Good luck!