What seeds are you wanting to sow? Many seeds don't need any cold stratification to germinate. I sowed about 5 types of Echinacea at the end of May and have many small seedlings now. They did not need any cold treatment.

For those seeds that have a tough seed coat and truly need 1-3 months of cold wet conditions to germinate, then it's easiest to just wait and sow them in the fall or winter. They are ideal for winter sowing, not summer sowing.