Growing Asparagus in a Rain Garden

Hi! I'm experimenting with growing asparagus in a mound set into a rain garden. At year 1 here, it seems to be flourishing. Anyone else try anything similar? I'm in Zone 6, which with climate change is slowly morphing to zone 7. I haven't had to water the asparagus even once myself. We get 40 inches of rain annually, and my rain garden is an outlet from two sources: 1) rain barrel overflow and 2) outlet for a French drain meant to relieve water seepage into our basement between our home and a neighboring building, only a few feet away.

Interested to hear other experiences.