I think that Daniel will have much more luck with that process than I do, his shaded area would be fine for Bonsai providing he follows the rules that I always break like watering and feeding them regularly! To be honest true shade in my own garden is a near illusion.I have a number of "bonsai" native trees, which I will keep in their pots and plant out, trimming each year as I do with my normal bonsai. For example I have 15 years + sycamore and birch less than 12 inches high.