black eyed susan

I took some seed heads off my dads black eyed susan last autum,and have tried twice to germinate them (in two seperate unheated propagators,in my unheated greenhouse),it is now comming upto 5/3 weeks respectivley since sowing and nothing,am i to eager or have i done somthing wrong,other seeds sown have come through fine but i really want these to do well,any ideas gang.

 

Were the seeds properly ripe, and were they stored cool and dry through the winter. Thats the most important thing, any doubts might aswell buy a packet, not that expensive.
Just noticed, UNHEATED propagator in UNHEATED greenhouse, it might get warm during the day but its still cold at night. They really need a steady temp above 15 deg C.