The butterfly bush, aptly named as its large, fragrant flowers attract butterflies, blooms from mid-summer into fall in an assortment of colors such as violet, red, pink, blue, yellow and white. This low-maintenance bush can grow from 3 to 10 feet tall and wide. Although they can be somewhat scraggly in appearance, taller bushes make a striking statement when planted near a fence or wall or grouped with other bushes in the garden. Plant your bare-root butterfly bush before winter and enjoy the rewards of this fast-growing bush next summer.
Prepare the soil in the fall before the first frost. Select an area that gets at least six hours of full sun daily. Loosen the soil with a gardening fork or tiller to a depth of 1 foot, and work in compost to create the well-draining soil butterfly bushes require.
Dig a hole twice as wide as the bare roots and just as deep. Mound up the soil into a cone in the bottom of the hole.
Place the plant into the hole with the roots laying over the mound of dirt on the bottom. Spread the roots out, keeping all of them in contact with soil. This eliminates air pockets from forming, which can kill the plant. Plant the bush at the same depth as it was grown in the original container. Look for the soil line on the stem of the bush above the roots, and adjust the plant in the hole as needed.
Fill in the hole while firming the soil around the roots, working it in with your fingers. Keep your plant straight as fill in the hole with more soil. Firm the top of the soil with your hands and form a well around the plant 1 foot out from the main stem. This will hold in water and nutrients and help establish the plant.
Water the newly planted bush deeply with a garden hose, allowing the water to trickle out slowly for about 30 minutes. Your new bush should get about 1 inch of water weekly. Allow it to dry out between watering. A bare root bush is still dormant and should not get too much water until the following spring when it begins to grow. Once established, a butterfly bush is drought tolerant does not require more than 1 inch of water a week.
Fertilize your bush in the spring after the last frost has passed. Use a complete fertilizer, 15-15-15, which will cause the bush to come out of dormancy and begin growing. Apply a balanced fertilizer each spring.
Apply a 2- to 4-inch layer of mulch, such as shredded bark or straw, around the newly planted bush to protect the roots from cold winter weather. Each spring, apply a new 2-inch layer of mulch around the bush to control weeds and retain moisture in the soil.