<p>Mediterranean type of climate is challenging for plants, forcing them to evolve different strategies to cope with it. Juveniles show anatomical and morphological differences from adults and grow under different micro-environment, factors that may affect their water relations. The aim of this study was to search for plasticity in leaf-water relations parameters which contribute to turgor maintenance, between adults and juveniles of three characteristic plant growth forms and evaluate if this plasticity is similar at the clearly distinct seasons in Mediterranean regions. For this reason, seasonal measurements of water potential, stomatal conductance, cell wall elasticity, capacity for leaf cell osmotic adjustment and redistribution of water between leaf symplast and apoplast, were conducted in adults and juveniles of the sclerophyllous evergreen <i>Nerium oleander</i>, the semi-deciduous <i>Phlomis fruticosa</i> and the winter deciduous <i>Cercis siliquastrum</i>. Differences between adults and juveniles were mainly observed during summer, when juveniles presented worse water status and lower stomatal conductance than adults. Juveniles of <i>N. oleander</i> showed less elastic cell walls, increased osmotic adjustment and redistribution of water in favour of symplast during summer, while juveniles of <i>C. siliquastrum</i> showed more elastic cell walls than the corresponding adults at all seasons. These water adjustments could help juveniles to draw water and/or retain turgor. On the other hand, juveniles of <i>P. fruticosa</i> had similar water relations to adults, showing that the wide repertoire of water adjustments of <i>P. fruticosa</i> is already present from the stage of juvenility. Leaf water relations differences between adults and juveniles were not expressed in all seasons but mainly during the drought period, while no age differences were detected in the semi-deciduous shrub.</p>