Goldfinches at nyjer feeder

I’ve been investigating to see if we can plant Nyjer bird seed from the package seed we buy for birds. Nyger, niger or thistle bird seed are all names for the same bird seed from Africa. The official name, nyjer, was picked in 1988 so as not to offend anyone with the name niger or to confuse anyone about it possibly being a thistle seed. It is not our common thistle that we consider a weed here in the US.  Finches, pine siskins, and goldfinches particularly like it but other birds do not. To prevent any weed seeds that may be in the nyjer  and to prevent the non-native plant (nyjer) themselves from sprouting, all nyjer seed is now sterlized by heat and therefore not able to germinate. Perhaps this is for the best because even though it is not a weed, it spreads like one in it’s native land but does not grow well in the US. This heat sterilization is the reason for its high cost. So unlike the BLACK OIL SUNFLOWER SEED that we CAN plant and harvest for the wild birds, we will NOT be able to grow thistle. Too bad cause it’s so expensive.