KNOXVILLE, Tenn. (WVLT) - No, that wasn’t Styrofoam that you saw on the side of the road Wednesday morning. Tens of thousands of frost flowers formed on what was then the coldest morning of the season.

These frost flowers typically happen for each grass stem only once per season. And as we head to delay the first freeze, and this was the coldest day of the season, they were everywhere.

Here’s how it works: think of a pasta machine or your kids Play-Doh toys. The ice is excluded from late season grasses following the first big freeze.

When the temperature gets well below, freezing liquid water freezes into ice crystals. As you probably remember from science class, when water freezes it expands. The expanding ice inside of grass stems forces the stock of the grass to split apart. Once that happens, the action of water forces this ice outside into ribbons. This process is the same extrusion that you use to make pasta.

For some areas that didn’t get quite as cold on Wednesday, frost flowers are still possible later in the season.