Butterfly Bush Container Growing
If you’re serious about growing a butterfly bush in a pot, a whiskey barrel may be your best bet. The pot must be deep enough to contain the roots and heavy enough to keep the plant from toppling over. Whatever you decide to use, be sure the pot has at least a couple of good drainage holes. Consider a rolling platform. Once the pot is planted, it will be very difficult to move. Fill the pot with a lightweight commercial potting mix. Avoid garden soil, which becomes heavy and compacted in containers, often resulting in root rot and plant death. Choose the cultivar carefully. A huge plant that tops out at 8 or 10 feet (2-3 m.) may be too much, even for the largest container. Dwarf varieties such as Petite Snow, Petite Plum, Nanho Purple, or Nanho White are limited to heights and widths of 4 to 5 feet (1-1.5 m.). Blue Chip maxes out at 3 feet (1 m.) in most growing zones but may grow to 6 feet (2 m.) in warm climates.
Caring for Container-Grown Buddleia
Place the pot in full sunlight. Cut the plant back to 10 to 12 inches (25-31 cm.) in late winter or early spring. Apply a time-release fertilizer in spring. Water regularly. Although buddleia is relatively drought-tolerant, it will perform better with occasional irrigation, especially during hot weather. Buddleia is typically hardy to USDA plant hardiness zones 5 and above, but a container-grown buddleia may need winter protection in zone 7 and below. Move the pot into a protected area. Cover the soil with 2 or 3 inches (5-8 cm.) of straw or other mulch. In very cold climates, wrap the pot with a layer of bubble wrap.
