The house measures 10 inches x 5.75 inches x 4.75 inches. Planting Instructions: The smaller varieties of Allium should be planted 4″ deep and the larger varieties 7-8″ deep. Spacing 6-8″.Hardiness zones 4-8. The plant grows 12-36 inches tall. The flowers bloom in early to mid-summer. The flower heads are egg-shaped and reach a height of 1-3 inches. The butterfly house also includes 25 Sphaerocephalon Allium bulbs. This allium is also known as drumsticks. These pretty flowers open green, then start to turn a purple crimson color from the top creating an unusual two-tone drumstick flower head. In return for their hard work, you can provide them with a protective home with this 100 FSC-certified wooden butterfly house. Attract beautiful butterflies to your garden and they will help pollinate your garden flowers and plants.