Buddleia is best planted from spring to midsummer so the plants have ample opportunity to develop a good root system to sustain them through the winter. Avoid fall planting, especially in zones 5-6.
Choose a spot in your landscape that receives full sun, meaning at least 6-8 hours of sun per day with most of that coming in the afternoon. This is true even in very warm, southern climates. Buddleia does not grow in the shade.
Buddleia needs excellent drainage to survive. Often when the plant fails, it is because it received too much moisture and the roots started to rot. If you have an automatic sprinkling system, do not plant your butterfly bush where it will be inundated with water on a regular basis. Sandy loam soil is naturally well-drained, but if you have clay soil, you will need to take special precautions or grow your butterfly bush in a large container.
When planting in clay soil, we do not recommend trying to amend the soil. Instead, plant it in a raised bed or plant “high”. Planting high means instead of positioning the shrub even with the ground level like you would other plants, dig a slightly shallower hole and position it so that the base of the plant is a bit higher than the ground. This encourages water to drain away from the plant rather than settling around it.