Plugs of Arabis `Spring Cham', Cerastium `Columnae', Salvia `Blue Queen', and Saxifraga `Purple Robe' (128 plugs/tray) were cooled at 2 to 3C for 0, 4, or 8 weeks. Plugs were potted in 10-cm containers and placed in warm (20C day, 17C night) or cool (10C day, 8C night) and provided with various long- and short-day combinations. In general, all taxa flowered more rapidly in the warm house, but were not significantly taller. Arabis showed no response to cooling or photoperiodic treatments, but Cerastium and Saxifraga had significantly longer internodes when subjected to increasing number of LD cycles. Plants of Salvia and Cerastium also flowered more rapidly when subjected to increasing cycles of LD, but height of Salvia and Arabis was reduced when LD were followed by SD. Other species of perennials will also be discussed.