We are starting to see a lot of native grasses this spring. Our cooler than normal temperatures and increased rain fall are creating the perfect growing conditions. We are seeing Poa Annua (annual bluegrass) Flowering right now and some Poa Trivialis (rough stalk bluegrass, no seed heads growing taller).　 Seed heads will fall off and lay in the soil waiting to germinate this fall and start the process all over again. With regular mowing you can achieve the "illusion" of a lawn without weed grasses. We employ a Weed Grass Control Program (WGCP) that deals with this growth and germination. This is the only way to control the growth and germination of "off type" grasses.  If you want to get on the WGCP, it consists of 2 spring, 1 fall and 1 winter application. You could start now if it is really bothering you or wait until fall to get the germination.　 If you start now you may need to reseed because the product used is pretty hard on the poa grass plants and your lawn will thin out a bit.  Either way, once you start on the WGCP you should stay on it. If you don't, the native grasses will come back in a year. They grow really well here from October thru March.