I currently have three different cultivars of Japanese maples and am planning on getting a few more to have a extensive Jap. Maple collection in the end. I have seen a few nurseries that deal exclusively in Japanese Maples attest that Dyna-Grow (7-5-9) being the best Fertilizer for Japanese Maples. I always wondered if it was true (or if it was just a sponsorship type deal) and therein what was the best or is there even a best?? Does anyone know of any actual study done on Jap. Maples and their specific needs? I have seen a few fertilizers say they are meant almost exclusively for and work best for Japanese maples such as 'Peace of Mind Organic Fertilizer' (4-8-5) and 'Happy Frog Organic Fertilizer' with the same NPK rating (if there's even a difference between the two). Both seem to also contain Mycorrhizae and Humic acid.