Matrically priming seeds of common Kentucky bluegrass (Poa pratensis L.) and `SR8300' tall fescue (Festuca arundinacea Schreb.) in fine, exfoliated vermiculite (-1.5 MPa, 20 °C, 4 days) increased subsequent germination rate but did not increase germination percentage or synchrony. The lowest seed: vermiculite ratio (dry weight basis) to provide full priming benefit for seeds of Kentucky bluegrass and tall fescue was 1:10 and 1:20, respectively. Storing Kentucky bluegrass seeds primed in 1:10 (seed:vermiculite) in moist vermiculite for 10 days at either 5 or 20 °C did not reduce germination rate in comparison to primed seeds that were not stored. Primed tall fescue seeds could be stored in moist vermiculite (1:20, seed:vermiculite) for up to 10 days at 5 °C with no loss of priming benefit, but storage for only 2 days at 20 °C resulted in germination. Primed seeds of Kentucky bluegrass (stored for 0 or 10 days at 5 or 20 °C) or tall fescue (stored 0 or 10 days at 5 °C or 2 days at 20 °C) resulted in more rapid germination and seedling emergence, and greater seedling shoot fresh and dry masses than was the case for nonprimed seeds.