"All that has been selling, and when the weather warms up, it'll go back to selling," he said.

The weather wasn't a threat to those gardens, though, said Gene Sumi, horticulturist at Homestead Gardens in Davidsonville. The snowfall had more affect on business — things were unusually quiet there Monday — than on the health of most of the center's plants and flowers, he said.

Most of Homestead's outdoor plants, from pansies to roses and fruit trees, are hardy enough to withstand considerably colder weather than Monday's, he said, and snow can even be a boon.

"Snow actually helps a lot of wintering-over plants by acting as insulation," he said.

Still, the unseasonably cold weather is potentially harmful to a variety of perennials the garden center has brought in from nurseries in North Carolina and Georgia, where they were planted during a growing season that starts about a month earlier than Maryland's.

"We're moving those inside," Sumi said. "That's really just an inconvenience, and again, it has to do with the temperatures, not the snow."

The snow isn't expected to stay around for long, with high temperatures forecast to hover around 50 degrees for the rest of the week.

But that's still well below normal for the month. Normal highs approach 60 degrees by the end of March in Baltimore.

The average temperature this month was running 2 degrees below normal through Sunday, at 40 degrees. If the trend holds, it would be the first string of consecutive colder-than-normal months since December 2010-January 2011.

Baltimore Sun reporters Alison Matas, Jonathan Pitts and Alison Knezevich contributed to this article.