May is a spring month where we see tremendous changes with the forests around us. The woods begins with a bare landscape, much as we saw throughout the winter (without the snow). But as we grow through these 31 days, we’ll see a continuous amount of green leaves opening on the branches. Starting with the shrubs and small trees, the greening progresses to the tops of the larger trees; many of these big woody plants are among the last to take on this attire. Longer and warmer days continue and bring on this new canopy.
Leaves, when they first emerge, are composed of soft material. Just as the leaves open for the new season, so does the crop of new insects that eat these tasty morsels. Many of these herbivores are caterpillars and if unchecked, they could cause the trees to return to the barren state they just came from. The time is right for insectivorous birds to arrive and feed on this large population.
With excellent spring timing, these hungry avian feeders come back from their winter sites. The Northland is home to many kinds of songbirds that appear on the scene now and they devour the caterpillars. About two dozen species of warblers, several kinds of vireos, along with orioles, grosbeaks, hummingbirds, thrushes, swallows and flycatchers, return during May and find plenty of food awaiting them. After their long northing flight, they are hungry. Throughout the days they eat and rest, occasionally mixed with mating and territorial songs. With this birdfeeding bonanza, the trees are able to grow their leaves to full size. The woods takes on a green appearance. As we exit this month in a few weeks, the forests will be fully leafed out and shady.
As much as the trees need to grow their food-producing leaves in the sunlight, so do the plants of the forest floor need this light. Their days in the sun are very limited and so they need to grow quickly, form their leaves and flowers and get pollinated by the ever-growing list of butterflies, bees and other insects. And just as soon, they will fade. With such limited time, many of the spring wildflowers are referred to as ephemerals, a term meaning short lives.
We don’t think of all that as we wander among these spring wildflowers of the first half of May. The forest floor is alive with many species that reveal a colorful vernal bouquet. Whites and yellows dominate the petal colors at this time but a few other hues are here, too. Bloodroots, strawberries, wood anemones, toothworts, trilliums (both large-flower and nodding) and some trout-lilies give this light layer to the woods. Other trout-lilies and a couple of kinds of bellworts bring yellow-gold to the scene. Hepaticas vary from light to blue to purple. Spring beauties are usually pink and the cryptic purple flowers of the wild ginger lie on the soil. The violets of several kinds are white, yellow or purple.
This colorful group of plants blossoms quickly to be replaced by shade-tolerant types later in the month. We usually take note of the woodland bouquet in early May, but colorful flowers prevail elsewhere as well. As we pass by the many wetlands that exist in the area, we’ll note bright yellow-gold emanating from here. This is the time of the flowering of the marsh marigolds.
Also known as cowslips (a term unfortunately applied to another flower in some parts of the country), these yellow-flowering plants are a marvel in their growing abilities. Emerging from a site that was under ice maybe just a month ago, they rapidly grow to form large, nearly circular, leaves. These green structures may be at least 6 inches across. The plants still have enough energy to produce clusters of flowers. I usually see the first of these flowers opening in late April. These first buds are quickly followed by more and by this time in May, they stand up to nearly a foot tall and contain numerous newly open flowers. Typically, these impressive florets are about 1 to 1 1/2 inches wide with five petals (some variation here) and are a bright yellow-gold.
It is hard to go by the wetlands at this time and not see them. They add much to a swampy wet site that may have little else in bloom now. With plenty of sunlight, they are in no hurry with their flowering season and they will continue to bloom for a couple of weeks. But in early May, we can witness this golden-glow from the wetlands and the varied bouquets in the woodlands. Temperatures are fine, the mosquito population has not yet reached its peak and so we are invited to go out and see and take a closer look at this annual spring flora color show.