Powell's brother-in-law Kirk Graves told The Associated Press that his mother gave up a plot tentatively reserved at Woodbine Cemetery overlooking the boys' final resting place.
"We felt very strongly that it wasn't appropriate to put him anywhere near the boys, and we did our best over the last 48 hours to convince her to do something different," he said. "It wasn't that hard to convince her - she just got started off on the wrong path."
Powell's mother had realized early this week that no one else was planning for what to do with Josh Powell's remains, so she visited a few cemeteries "cluelessly" picked a gravesite just up the hill from where the boys are buried, Graves said.
The decision prompted a public firestorm. The parents of Susan Powell threatened legal action to keep Josh Powell from being buried so close, and the anti-crime organization Crime Stoppers of Tacoma-Pierce County purchased the plots on either side of the boys to ensure that he didn't wind up next to them.
Powell was a suspect in the 2009 disappearance of his wife Susan Powell. He killed his 5- and 7-year-old sons and himself in a gas-fueled blaze on Feb. 5.
The Associated Press contributed to this report.