Summer snowflake (Leucojum aestivum 'Gravetye Giant' ) is a bulbous perennial native to central Europe and the Mediterranean. It blooms in mid spring (April to May), bearing nodding, bell-shaped, white flowers atop arching, hollow stems. The strap-shaped, glossy, dark green leaves create an upright, vase-shaped clump of foliage. Plant the bulbs in fall in well-drained soil in full sun to part shade 3 to 4 inches deep. Reliably hardy and long-lived in Chicago-area gardens, this plant has been in cultivation long enough to be an indicator of abandoned homesteads.