They aren't called 'Butterfly' bushes for no reason! With their long bloom season and nectar rich flowers, butterflies and hummingbirds flock to these easy-to-grow plants all summer. Tiny flowers form to create bottle-brush spikes that come in a wide array of colors. The tough plant has an uprightly arching habit. Pruning can be done at any time of year; in cooler climates, it is easiest to treat the plant as a perennial and in early spring cut all branches to about 12-in. from ground. The shrub is fast growing and will quickly reach its mature height.