Trees, shrubs blooming ahead of schedule

Rob Zimmer

A warm start to the spring season has caused a number of native forest trees and shrubs to begin blooming, in some cases, almost a month ahead of schedule.

Even in our own backyards, we can see the early tree and shrub bloom by examining the twigs and branches of our own woody plants.

Many of our maples are in full bloom now with the warmth of the March sun. Maples begin blooming far up in the treetops, closest to the sun, then work their way down to ground level. Sugar maples, swamp maples, red maples and silver maples are already in bloom in much of our area.

Look closely at the treetops to see the red haze that signals the bloom overhead. With a closer look, the reddish flower buds are adorned with golden pollen stamens, creating a spectacular floral showcase in miniature.

This past week, as I walked along the trails at Navarino Wildlife Area, I noticed that the hazelnuts are all in full spring bloom, as well. This is about a month early; I usually don’t find hazelnuts in bloom until mid-April or so.

Here in Wisconsin, we have two varieties of hazelnuts, the beaked hazelnut and the American filbert. They are very similar in bloom and leaf, however the husks are completely different that cover the growing nuts.

Hazelnuts produce both male flowers and female flowers. The male flower is a long slender catkin adorned with greenish yellow pollen. The female flower grows from an ovary-like structure along the branch and resembles a tiny sea anemone with wine-colored or reddish tentacles that emerge to capture the sticky pollen.

Also in bloom along wetland shores and damp places is tag alder. Tag alder, like hazelnut, produces both male and female flowers. The male flowers are beautifully purple or maroon-colored catkins, while the female flowers are short, squat cone-like structures on the branches.

The birches are also loaded with beautiful catkins now in early spring. Paper birch, yellow birch and river birch are all sporting these beautiful floral structures.

Of course, the native pussy willows are now beginning to pop in abundance in mid-March. The silvery, fur-covered catkins of a variety of different willow species can be seen in area wetlands and shorelines, as well as our own backyards, where cultivated varieties are planted.

Willows are not the only variety of woody plant to produce fur-covered catkins. All of the aspens — including quaking aspen, big tooth aspen and cottonwood — also support large, silvery, fur-covered catkins now in the middle of March.

Enjoy exploring the world of flowering trees and shrubs in your own backyard this month.

Rob Zimmer is a nature and garden author, public speaker and radio show host on WHBY. Readers can find him on Facebook at