I recommend "Old-Fashioned Flowers, and other out-of-door studies" to readers who appreciate beautifully crafted prose, philosophical reflections on nature, and a deep connection to the natural world. Maeterlinck's book offers a glimpse into the wonders of the natural world and invites readers to see the world around them with new eyes. Whether you are a nature enthusiast or simply appreciate well-written literature, this book is sure to inspire and uplift you with its timeless wisdom and enchanting descriptions of the beauty found in the simplest of things.