Algoflash here in Europe is selling an osmocote slow release type fertilizer (it calls 'basacote') that it says is good, for among other trees, japanese maples in pots (+ other hedges, shrubs). It's 16-8-12 + Mg + S + minors, but it is active over 8-9 months, not 6. This would work from March to November, then. (The temperatures in the warm months where I am are usually not as extreme as in the States, so there could be less of a chance of fertilizer burn.) Is an 8-9 months formula ok or should I only place a slow release fertilizer once the maples start showing leaves, and use a 6 months formula that goes to October? (I could also of course simply remove the cubes come October...). Any thoughts, advice or experiences shared would be welcome.