Butterfly bush, a perennial flowering shrub also known by its scientific name, Buddleia davidii, is native to warm areas of Africa, Asia and the Americas. In the United States, the shrub thrives in hardiness zones 5 through 10. Gardeners value butterfly bush for its colorful, fragrant flowers that appear in summer in shades of white, pink, red or purple. The plant also attracts butterflies, making it a popular choice for butterfly gardens. The short-lived shrub may only last a few years in the landscape, but it grows quickly and flowers abundantly while it's there.
Plant butterfly bush during late spring or early summer to allow the root system time to establish before the onset of winter. Choose a location that receives full sunlight throughout the day for optimal flowering and growth. Space butterfly bush plantings 4 to 5 feet apart.
Apply a 2-inch layer of mulch over the soil surrounding the plant to reduce problematic weeds, insulate the root system and improve moisture conservation. Allow about 3 inches of space from the base of the plant to the beginning of the mulch band to allow air circulation.
Water butterfly bush when the top 4 inches of soil are dry to the touch, about once every week. Place your finger in the soil to check if the plant needs water. Reduce the frequency of watering to once every 10 days during winter, when the plant is dormant.
Feed butterfly bush once each year, beginning with the second year of growth. Apply a balanced 10-10-10 NPK fertilizer during early spring, just before the plant begins actively growing. Follow the instructions provided by the manufacturer for correct dosage.
Use pruning shears to cut butterfly bush to within 6 inches of the ground in late fall, just before the onset of winter, to protect the shrub from unnecessary cold damage and induce dormancy. Continue to water it regularly, about once every 10 days, and new growth will appear in the spring.