Kentucky bluegrass (Poa pratensis) has not produced flowers when the plants were held continuously on the long days and moderate temps, which are optimum for the flowering of plants brought from the field in late fall or midwinter. Both low temps. and short days have been required for floral induction. No flowers have been produced on plants held continuously at temps. above 15 C, irrespective of the photoperiod, and only an occasional flower on plants held at lower temps. on 18-hr. photoperiods. After the fall induction period flowering was greatest at moderate temps. (13-18 C) and photoperiods of 15 hrs. or more. Flower production per pot has been increased 10 times by fall fert. with (NH4)2SO4 and reduced by fall clipping. These are considered to be floral growth responses following floral induction under the low temps, and short days of the fall.