Well there’s something you don’t see every day: icy casing of apples hanging off a tree. Rather appropriately, they’ve been given the moniker “ghost apples”, but what the heck are they?
Currently going viral on Twitter, these rather striking features were spotted in West Michigan by one Andrew Sietsema, who posted the images on his Facebook page. He told me that he’s not quite sure how they formed, but suspects that after some rather cold conditions and plenty of chilly rainfall, the surface of the apples froze over. The apples themselves, which are resistant to temperatures that freeze water to a greater extent, remained intact.
Later, it was just warm enough to allow the encased apples to take on some of that water and turn into a mush. “When I pruned a tree it would be shaken in the process, and the mush would slip out of the bottom of the ‘ghost apple’,” he explained. “Most apples just fell off, ice and all. But quite a few would leave a cool ‘ghost apple’ behind.”
As these apples happen to be of the Jonagold variety, Sietsema has come to calling them “Jonaghosts.”
As far as I can tell, this phenomenon hasn’t really been seen before. During a brief Twitter exchange, I wondered if botanist extraordinaire James Wonghad seen anything like this before, to which he replied: “No!” before noting that he isn’t sure how a frozen apple would rot and fall out of the casing like that.
Some of you may be wondering if this is too good to be true. Are they legitimately real things, or is this a rather glorious sleight of hand? At this point, I can’t say for sure. If there are any horticulturalists out there that might have any insight as to how these apples formed, or how rare the set of circumstances need to be for ghost apples to appear, please do get in touch.
Sietsema, who studied horticulture himself at Michigan State University, said that he understands that the pictures might provoke some skepticism because they are certainly quite strange. Saying that, he says that he’s sure it’s happened before, but added that “most pruners are hard at work instead of taking pictures like me.”
William Shoemaker, a retired fruit and vegetable horticulturalist from the University of Illinois, pointed out that those apples, leftover from harvest, just went through a week of “exceptionally cold weather” due to the polar vortex. “Besides being somewhat mummified, they could also be rotten,” he explained. “It happens a lot with apples left on the tree. They maintain their form, but their substance gets closer to applesauce.”
When their temperature drops to around -18°C (around 0°F), their structure collapses, and a few could “spew their rotten contents successfully.” Although some may wonder why the apples didn’t freeze solid during the polar vortex, Shoemaker noted that the apple has a significant acid content, so it would have to get exceedingly cold before it froze solid.
“It’s certainly unique, but I would guess it has happened before,” he said, adding: “but it probably never had exposure to a journalist before.”