Thursday May 15, 2008

Campus Report May 15, 2008

University alumnus and landscaping company owner Marty Grunder will plant no annual before May 15.

Dayton landscaping company owner Marty Grunder doesn't plant an annual before May 15.

"In my 25 years in business, we've always kept with that," said Grunder, the president and CEO of Grunder Landscaping and a 1990 UD business graduate. "That's pretty standard — Mothers' Day or May 15. We start putting annuals in next week."

But the custom may be rooted as much in religious tradition as it is in science.

Meteorologically speaking, Dayton's frost date — when the likelihood of a frost is less than 10 percent — isn't May 15; it's around April 22, according to the National Climatic Data Center of the U.S. Department of Commerce's National Oceanic and Atmospheric Administration.

So why do so many people think it's May 15? Chances are good that they learned it from their European-descended grandparents.

In southern Germany, many gardeners don't plant until the end of the "Eisheilige," the four successive feast days of the "ice saints" — Mamertius, Pancras, Servatus and Boniface — May 11-14. The chilly period — a fairly typical May phenomenon in the northern hemisphere, though not always on those days — ends with "Sophientag" on May 15, named for St. Sophia of Rome.

Delphi engineer and 1990 UD graduate Tim Schlangen of Kettering, who was in Germany on business the first week of May, learned of the custom from a German colleague at Delphi's office in Rüsselsheim. At lunch one warm afternoon, the German engineer, Stephan Fath, who lives in Gau-Bischofsheim, expressed his eagerness for "fünfzehnten Mai" so he could plant his garden.

Schlangen said, in German, "May 15? We use the same day, though we're not on the same parallel."

So came Fath's explanation, which is affirmed by Elke Hatch, a native of Germany who has taught German at UD since 1985. She remembers the custom well.

"My mother used the term," Hatch said. "She was from a mountainous area in what now is the Czech Republic. The climate there was harsh ... so you probably had to adhere to the Eisheilige rule. Where I grew up, however, about two and a half hours by car south of the North Sea in West Germany, the climate is much milder."

Global warming may be taking off Eisheilige's edge.

"As global climate change sets in, we can expect that it will get warm sooner but that weather will become more erratic," said UD biology professor Brother Donald Geiger, S.M., who doesn't always wait until May 15. "The way I tend to do it is to look at the long-term forecasts for night temperatures starting about May 10. This year, the pattern looked favorable, so I planted my tomatoes, peppers and eggplants on May 10."

So, while it's not absolutely necessary to wait — Hatch's father's garden today is on a southern slope of a valley protected from the north by a range of medium-high mountains, and it's probably safe to plant earlier — many gardeners, like Fath, still do. They don't want to put their plants at risk of a "cold Sophie," the nickname of an uncharacteristically cold day in May that is the inverse of autumn's Indian summer.

It's probably no surprise that it, too, bears a saint's name: St. Martin's Summer is named for St. Martin of Tours, whose feast day is Nov. 11.