Dexter Pakula

Categories: June 2, 2026 It’s mating season! In the spring, male frogs and toads begin to search for mates. They call repeatedly, often throughout the day, though particularly at dusk, attempting to attract females. The Arboretum is home to multiple frog and toad species. In the early spring, you might hear Western Chorus Frogs (Pseudacris triseriata), Wood Frogs (Rana sylvatica), and Northern Leopard Frogs (Rana pipiens).

Categories: February 27, 2026 Trees exhibit a variety of fascinating behaviors and phenomena in the winter. (See the Arb Note from two weeks ago to learn more about exploding trees.) We are nearing the late winter and early spring, when freeze-thaw cycles drive sap flow, and sap for syrup production is extracted. As the temperatures begin to increase toward the end of winter, days are frequently above freezing, and nights are below freezing.

Minnesota is awfully cold right now. A lobe of the polar vortex has shifted southward, bringing Arctic air into the lower 48 states. You may have heard rumors of “exploding trees.” This nomenclature is a somewhat accurate description of a real problem that trees face in the winter. The wood of a tree is divided into different parts, which is what brings about this phenomenon.