Do very heavy elements form only in Supernovae? ?

It's generally accepted that all such heavy elements here on Earth are the product of previous supernovae. Stars simply can't form any element heavier than iron, no matter how big, because doing so requires more energy than is released. The only exception is the artificially created elements. For instance, all naturally occurring plutonium has decayed away. The only plutonium here on Earth has been produced in nuclear reactors.