After a full day working out in the garden doing spring clean-up, I decided to keep tonight's propagation project simple. I sowed two small flats of petunia seeds, using a mix of potting soil and perlite (about a 2:1 mix). Petunia seeds are so tiny! All you can do is sprinkle them carefully on the top of the soil, press them in (but don't cover them with more soil) and hope that you haven't sowed them too thickly. They need light to germinate so tomorrow they'll go out in the greenhouse.