Ghost apples are one of nature’s most visually striking and unusual phenomena — not a variety of apple, but a rare ice formation that occurs in specific winter conditions. If you’ve stumbled across photos of what looks like hollow, translucent apple-shaped shells sitting on bare branches, you’ve seen ghost apples. Here’s the fascinating science behind them.

What Are Ghost Apples?

Ghost apples are icy shells in the shape of apples that form on apple trees after a specific combination of freezing rain and cold temperatures. They are not a fruit variety or food product — they are purely a weather phenomenon, sometimes called an ice glaze or shell.

The term “ghost apple” went viral in early 2019 after Michigan orchardist Andrew Sietsema shared photos of the formations on his apple trees during a winter ice storm. The images spread worldwide, capturing people’s imaginations with their eerie, beautiful appearance.

How Do Ghost Apples Form?

Ghost apples form through a precise sequence of natural events:

1. Freezing rain coats the apple — an ice storm coats each apple on the tree with a thin layer of ice, moulding to the exact shape of the fruit.
2. The apple freezes but rots internally — many apples left on trees through winter have already begun to decompose. As temperatures drop, the rotting flesh, which has a lower freezing point than water, stays soft or mushy inside while the outer ice shell hardens around it.
3. Wind or handling dislodges the apple — when the tree is shaken by wind or movement, the soft, mushy apple inside slides or falls out of the bottom of the ice shell, leaving behind a perfectly formed, hollow apple-shaped ghost of ice.
4. The hollow ice shell remains — the ice mould holds its apple shape on the branch, often for hours, until temperatures rise enough to melt it.

Where and When Do Ghost Apples Appear?

Ghost apples are rare and require a very specific set of conditions:

• Freezing rain (not snow) that coats surfaces with a layer of ice
• Temperatures hovering just at or slightly below 0°C
• Apples that were left on the tree into winter and have begun to decompose
• Wind to shake the apple loose from its ice mould

They are most commonly reported in northern US states, Canada, and parts of northern Europe — regions that experience winter ice storms. They typically appear in January and February during or after ice storms.

The Science of Ice Glazing

The ghost apple phenomenon is a stunning example of differential freezing points. Pure water freezes at 0°C, but decaying organic matter — with its sugars, acids, and breakdown products — has a lower freezing point. This means the apple flesh can remain soft or liquid inside while water freezes solidly around it, creating a natural mould.

This same principle explains why salt is used to de-ice roads (adding solute lowers the freezing point of water) and why sea water freezes at a lower temperature than fresh water.

Are Ghost Apples Edible?

No — ghost apples are not edible and are not a food product. The apple inside that falls out is decomposed and not fit for consumption. The remaining ice shell is simply frozen water. The phenomenon is entirely visual and scientific in nature.

Why Ghost Apples Capture Our Imagination

Ghost apples are a perfect example of how everyday natural processes can create something that looks magical or otherworldly. They are a reminder that weather, chemistry, and biology constantly interact to produce surprising results in the natural world.

Photographers and nature enthusiasts seek out ghost apples during winter ice storms for their hauntingly beautiful, sculptural quality. Each one is unique — shaped by the specific apple that formed inside it.

If you live in a climate with cold winters and have an apple orchard or backyard apple tree, keep an eye out after freezing rain for these incredible natural formations — they are genuinely breathtaking in person.