I live in Canadian Zone 5-6 (downtown Toronto near the lake) and want to plant a Japanese Maple on the rooftop of our building. Its only about 12 stories off the ground but obviously gets exposed to direct sun for most of the day. To complicate things they would be planted in the center of 5x5x5â² planters spaced 10â² apart and then filled with plants around them. (see photo)

I really want an alternating green and bright red combination like Fireglow or Oshio Beni and Pink Lace but realize they probably won�t be able to take the rooftop climate.

Any ideas? I�m stuck�