In previous abstracts (HortScience 23:707;24:121), ABA when added throughout the in vitro production cycle, reversed the tissue culture-induced rejuvenation of the day neutral strawberry `Fern'. Compared to benzyl adenine (BA) proliferated plants, ABA treated tissue culture-produced plants flowered earlier and had more adult leaf patterns. In the present study, we analysed endogenous ABA concentrations in the apices and unexpanded leaves of BA treated tissue culture-propagated plants, selved seedlings and propagated adult runner tip plants at 3, 7 and 15 weeks ex vitro, after germination or after runner tip propagation. Using pentadeuterated standards and single ion monitoring, ABA concentrations in tissue culture produced and juvenile seedling plants were significantly lower than adult plants at 3 and 7 weeks. By 7 weeks, only the adult plants were flowering. At 15 weeks, no differences in ABA concentration were significant and all three types flowered.