He revealed that he became familiar with this unique Aboriginal ritual when he visited Australia.
"When I was in Australia, they had a placenta tree that was on the river ... and all the placentas of all that tribe, all that clan, whatever Aboriginal tribe that was, all the placentas went under that one tree and it was this huge behemoth of just health and strength," News.com.au quoted him as saying, during an interview for CNN's program House Call.
"This tree was just growing taller and stronger above the rest of Mother Nature around it. It was gorgeous," he said.
McConaughey, whose girlfriend Camilla Alves gave birth to his son Levi Alves McConaughey on July 7, revealed that he had kept the placenta in the hope that it would fertilize the land.
"That's fertile ground, so to speak. So we're gonna plant. It's going to be in the orchards and it's going to bear some wonderful fruit," he said.