There is ample room for many voices in garden writing. I cannot think why it would be limited to a single style. I interpreted wasabi's piece as fiction, inspired by actual events and people. Not my cup of tea, but why can't fiction inspired by actual events and people be considered an appropriate vehicle for garden writing? I'm sure you well-read writers can think of many examples. The Orchid Thief? A Garden in Lucca? I haven't read these yet, so not sure, but I hope they illustrate my point.