Meanwhile Mr Yrjo Niskanen, head of emergency preparedness at Finland's national forest centre, said the U.S. president may have been referring to the practice of removing branches and loose material left in the forest after logging.
Two electric utilities companies said they had problems with equipment close to where the current blazes broke out around the time they were reported.
He told a local newspaper that he had briefed Trump on Finland's efforts to surveil and care for its forests, the Associated Press wrote, "but said he can't recall anything being mentioned on raking". "But the reality is, to manage every little bit of fuel with a rake is not practical".
Finnish social media users were quick to pile in, describing Mr Trump's comments as "rake news" and posting pictures of themselves brandishing the garden implement.
"You look at other countries where they do it differently, and it's a whole different story", he said.
"I was watching the firemen the other day and they were raking areas", Mr Trump said.
"If preventing wildfires were as easy as raking leaves, we would have done that by now, but it is a very complicated issue".
"Just been out in the forest raking".
Pyry Luminen posted a photo of herself pretending to hoover the forest floor, while Teemu Pasila tweeted that he was busy raking "some 228,000 square kilometres of forest".
He didn't mention that part of Finland is actually in the Arctic Circle. The wildfire has been called the deadliest and most destructive in the Golden State's history. And when it is, it's a very small problem.
On Sunday, authorities in California continued their search for the 1,276 people listed as missing.
For Armstrong, the erroneous remark added what she said was a new level of betrayal by the president.