I finally had the time to edit a year's worth of digital photos, including a series of moon garden pics. White and pale-flowered perennials -- primroses, daffodils, daisies, Davidia, and Japanese anemones -- showed up very well, of course, but so did magnolia blossoms. I don't know why I hadn't thought of magnolias as "moon garden flowers, but they provide not only blooms that "glow" in the dark, but also give structure to an amorphous mass of perennials. Besides the big southern magnolia blooms, the flowers of Magnolia officinalis, star magnolia, oyama magnolia, and such hybrids as 'Leonard Messel', 'Elizabeth', and 'Yellowbird' can glow like lanterns. On very bright nights, even my darker magnolias -- 'Randy', 'Rustica Rubra', and 'Susan' stand out in the moonlight.
Right now, in the "off season", white-flowered camellias keep the moon garden alive.