Commonly known as the butterfly bush, Buddleia davidii is a hardy, summer flowering shrub which is very easy to grow. All it needs is a sunny, open position and to be pruned hard in early spring. The plump nectar-rich flower spikes of this fast-growing deciduous shrub are very attractive to pollinators, especially butterflies. Deadhead regularly to encourage flowering all the way through to autumn. Buddleia is best planted in the autumn or spring after frosts

If you plant your Buddleia in the summer, remember to keep watering it until it is established.
Buddleias grow in most types of soil as long as it is well drained. If your soil is heavy clay, introduce some horticultural grit into the planting hole to improve drainage.
Plant in a sunny position.
Grow it in well-drained soil.