Summertime Blues™ (‘Helen Froehlich’) Chastetree blooms from mid summer to fall, producing large upright lavender blue spikes with black stems. Vitex x Summertime Blues™ comes from the hybridizing work of Kris Jarantoski, formerly of the Chicago Botanic Garden, so you know it’s winter hardy. The habit is compact and rounded, making Summertime Blues™ a good mid-sized shrub for sunny well-drained locations. Introduced by Plants Nouveau.