We grow this species from seed because it produces such an opulent display of intense blue flowers late in the season. Whorls of flowers are absolutely irresistible to pollinators when it blooms from late July to September. A mostly herbaceous species that dies to the ground. Much more dense and compact plants than other Caryopteris which we find kind of sparse and weedy. To 2′ tall and as wide. Full sun, rich, well drained soil with regular summer water. Takes drier conditions in rich soil. Mulch in fall. Cut back dead tops in spring when you see new growth begin. Aromatic. Bee’s, you plant it for the big ol black wooly bumble bees.
Family: Verbenaceae
Verbena rigida
Vigorous and floriferous perennial Verbena for tough areas. Spreading by underground stolons in rich to average well drained soil this deep purple flowering perennial covers ground in short order. Full sun and light summer water when established to lengthen bloom time. Even then it begins flowering in June and continue unabated for two months. To 2′ tall and 4′ wide. Give it room to spread and do not pair with delicate neighbors. Hellstrips, Insanely hot and dry south facing hillsides. Freezes to the ground in winter- returns from the ground when truly warm weather arrives. Moderately deer resistant.
Vitex agnus-castus ‘Sensational’
Excellent California selection of Chaste tree with thicker, bluer flowers. Large growing shrub with aromatic finely divided leaves in mid-July in PDX spires of blue flowers erupt from each branch tip. It remains in bloom for 3-4 weeks. And if you remove spent flowers more will appear. Full sun and poor to average well drained soil. No summer water when established. Attains tree-like status with great age. May be pruned back hard in spring to contain the ultimate size. Blooms on new wood. Long lived and hardy below 0ºF. Leaves appear late in spring- often not until mid-May. Be patient. Loved by pollinators and bumble bees specifically. A shrub in full bloom will be a haze of drunken bumbles who after a day of working will often fall asleep in the flowers of this shrub. Tolerates the hottest sites and is very long lived.