Spring Green-Up

By Coggin Heeringa, Interpretive Naturalist, Crossroads at Big Creek, Inc.

It’s almost St. Patrick’s Day, and folks around County Door are celebrating this weekend! At Crossroads at Big Creek, we’ve tailored our programs to align with St. Patrick’s Day and the seasonal phenomenon known as the “spring green-up.”

Our Science Saturday family program on March 15 (starting at 2:00 ) will feature an outdoor excursion (weather permitting) titled “In Search of Green.” On March 17, our Monday 1:30 adult program is a lecture called “Nature and St. Patrick.” On Tuesday, March 18, the 3;30 Environmental Exploration after-school program will be a “Seep Seek,” during which participants will search for locations where groundwater seeps into Big Creek by, as you might have guessed, looking for early signs of green along the banks.

“Green-up” refers to the period when plants break dormancy and resume growth. Scientific studies indicate that this typically occurs in early to mid-April in our region, although an early warm spell in March can accelerate the process.

Thanks to the moderating effect of Lake Michigan, our narrow peninsula may experience green-up earlier than the surrounding region. Even within our three Crossroads preserves, we observe localized microclimates, meaning that in sheltered, sunny areas, we may spot green around St. Patrick’s Day—or just as likely, we could experience a late-winter blizzard.

Green is associated with luck, renewal, and prosperity, and in Ireland, it is the color used to honor St. Patrick, the country’s patron saint. According to folklore, wearing green on March 17 makes you invisible to leprechauns—so they won’t pinch you!

However, that’s just one of the many myths surrounding St. Patrick.

One of the most well-known legends claims that the good saint drove the snakes from Ireland. While he didn’t, the fact remains that Ireland has no native snake species. It’s because of the glaciers!

During the last Ice Age, Ireland, like Door County, was covered by massive glacial ice for thousands of years. However, when the glaciers began to retreat approximately 10,000 years ago, Door County remained connected to the mainland, allowing snakes to gradually repopulate the area.

In contrast, as Europe’s ice sheets melted, rising sea levels isolated Ireland from the rest of the continent. This geographic separation prevented snakes from recolonizing the island, and to this day, no native snake species exist there.

For the same reason (rising sea levels, not St. Patrick), Ireland has only one native species of frog and one native species of toad. The lecture will also cover shamrocks and other related topics.The Junior Nature Club meets every Wednesday at 3:00 PM. Designed for children aged 3 to 5 and their accompanying adults, the program can accommodate siblings, and most sessions will take place outdoors as weather permits. This week, the group will be “Looking for Logs.”