One of my personal favorites, with strong sturdy growth, a lovely compact habit , masses of sumptuous, arching purple flowers complimenting the light green downy leaves and stems.
One metre or 3ft high and wide.
Needs a sunny position, enjoy watching the butterflies fly about.
Quite tender, it will put up with -5 C so therefore for most gardens its best to lift and bring under cover before replanting the following spring.
Well worth the effort.