Northern Minnesota phenology report: April 2009
By John Latimer, KAXE radio, Grand Rapids
Leatherwood remains one of my favorite plants. Its lovely yellow flowers festoon the shrubs under the sugar maples, basswoods, and red oak in late April. It is one of the most shade tolerant shrubs found in Minnesota. Shortly after the snow melts leatherwood blooms, and shortly after the blossoms appear the leaves begin to emerge. This early start takes place before the canopy overhead has had a chance to close off the sun’s light.
Since leatherwood doesn’t colonize open areas, nor does it respond well to fire disturbance, a healthy population is often an indicator of a climax forest. A forest that has a stable plant community with an established dominance of species and remains unchanged over time may be said to have reached its climax. Leatherwood can be the gauge of final successional stability on soils that are deep, rich in nutrients, and remain moist. So this spring as you gaze at the lovely yellow flowers check out the other plants and think about a forest that may go unchanged into the future.
May is truly the month of spring in northern Minnesota. The month begins with the blooming of the spring ephemerals, those early flowers on the forest floor that must get their blooming done before the trees leaf out. These flowers include hepatica, bloodroot, bellworts, and wood anemones, among others. Once the canopy begins to close in, the early spring flowers whither and the plants concentrate on leaf growth and food storage. Most of these early bloomers work from a root designed for storing energy. Without this reserve few would achieve this early start.
Hepaticas light the woods beginning in late April or early May. Once the bumblebees shake off their lassitude they quickly hone in on the blooms and perform the pollination. Hepatica’s furry stems arise from the leaf litter seemingly without leaves. The leaves are there, they’re just buried under last summer’s forest debris. Hepaticas have evergreen leaves. After the blossoms fade new leaves replace the old. Walk the same forest in the fall and these leaves shine bright green while all around them other vegetation fades to brown.
The flowers of the hepaticas may have as many as twelve sepals, and they may present nearly as many colors. The nineteenth century naturalist John Burroughs said of the hepatica: “What an individuality it has! No two clusters are alike; all shades and sizes; some are snow white, some are pale pink, with just a tinge of violet, some are deep purple, others the purest blue…” The one constant key to identity remains the dense fuzz on the stem.
Walking the forest and admiring the wildflowers may be its own reward, however it pays to stop and listen to the bird songs erupting all around. May brings an influx of birds like no other month. Perhaps the most anticipated, aside from the robins who came in late March, remain the ruby throated hummingbirds. These tiny dynamos of raw energy buzz into the northland around the first week in May.
I try to have my feeders out and ready by May fifth. I use a mixture of four parts water to one part sugar and no food coloring. It’s unnecessary and may actually do harm. Honey or brown sugar are also not recommended. I never let the nectar stand more than a week, at which point I will replace it with a fresh mixture. When I wash out the feeder I use a tiny amount of bleach to retard the growth of mold. It seems a little fussy but the hummingbirds are so small and sensitive that even the least amount of contamination can be lethal.
John Latimer is well known throughout northern Minnesota for his phenology work. He appears weekly on KAXE radio in Grand Rapids, and audio and twitter archives are available here. We hope his work will be a frequent feature on MyMinnesotaWoods. This article also appeared in the Duluth Senior Journal. It is printed with the author’s permission.