Similar to the American wisteria Wisteriia frutescens, this cultivar Wisteria macrostachya 'Blue Moon' was once grouped under frutescens, but now is given its own species name. The deciduous vine is found growing in Louisiana, Texas, Kentucky, Illinois, Missouri, and Oklahoma, but has been called the Kentucky wisteria. The blooming period is longer than frutescens, and is a bit lighter in color. Because it is often found growing near streams or swamps, this one might prefer to have plenty of water while in active growth in summer. 'Blue Moon' is less aggressive than the Asian types, and has excellent winter hardiness, with an ability to produce flowers in zones 3-4. The fragrant blooms are pea-like, and are out in June and into July each year. Flowers bloom somewhat simultaneously on the racemes thus producing a dramatic floral display.