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Phenology Report: Spring sprints toward summer

A juneberry bush in full flower. It has a twig with many small, white flowers with five narrow, long, white petals. The background is blurry. The image is captioned "Juneberry".
A juneberry bush in full flower. The Juneberry is also known as serviceberry, shadbush, or Saskatoonberry.

John begins this week's phenology show by stating, “This time of year, it’s hard not to get smacked in the face by some phenological occurrence.”

How’s that for an opener? Get ready — there's a surplus of surprise springtime slaps awaiting us this week.

Do you have observations to share? We’d love to hear from you! Get in touch with me (, John Latimer (, or text "phenology" to 218-326-1234.

Green canopy emerges

 Sage green bigtooth aspen leaves emerge in spring. The wide-based leaves have large, round-edged serrations on the leaf margins and red stems. The image is captioned "Bigtooth aspen leaves".
Sage green bigtooth aspen leaves emerge in spring.

Over the last week, the quaking aspen leaves finally broke bud. With the aid of a powerful spotting scope, John can observe the first hints of green emerging from the buds high in the aspen trees. However, he’s not always had that power (yes, that’s an optics pun): for many years, he waited for the aspens to begin turning a vibrant grape-green to mark bud break. For consistency’s sake, he continues to use that measure in his phenological records.

Using that measure, quaking aspen leaves emerged this year on May 9. Last year, they emerged on May 8. While May 9 is later than average, later leaf-outs have occurred in 1989, 1995, 1996, 2002, 2008, 2013 and 2014. Using other measures, however, John estimates this year is still in the Top 5 latest springs on record.

Using the well-named spotting scope, John was able to spot bud break on a big tooth aspen. The leaves on the big tooth aspens are a much paler, grayer green than on the quaking aspens. John likens them to a sage green or even lighter. Also, in a typical year, big tooth aspens leaf out 18-21 days after the quaking aspens. In late springs like this one, however, the gap shortens to nine to 12 days.

Big tooth aspen ID

These traits make it handy to distinguish the two species, even when the leaves have not yet reached full size. The big tooth aspens are lighter in color (nearly white when they first emerge) and leaf out later than the quaking aspens.

Other poplars, like the balsam poplar and the white poplar, are also leafing out. John describes the white poplar as a “scrubby, low, spread-out kind of a tree” with a shape like a box elder and pale whitish leaves. It gets quite tall but bushes out much lower to the ground.

The male flowers on birches are distended. The river birch outside the KAXE’s studio has catkins transitioning from a dark brown to a bright yellow: they are dropping pollen.

Tamarack in spring

Tamarack trees’ needles are emerging, and individual needles are now distinguishable. Previously, they appeared as small green cones, but they have begun to separate. On the tamaracks, you can also look for the yellow mushroom-shaped pollen cones. You’ll have to look closely: these cones measure a measly quarter-inch or less across. The female cones have tiny magenta tips and a green base.

White blossoms in the forest

 A white, five--petaled plum flower emerges from a twig.
A white, five--petaled plum flower emerges from a twig.

Forests are full of remarkable, white-blossomed shrubs. Two plants are largely responsible: the juneberry and the plum. (Technically, there are a couple plum species, but we’ll bunch them together for now.)

Juneberries will have leaves and flowers present at the same time. The leaves on the juneberry fold down the center like the pages of a book: as the leaves develop, they open further. All the flowers on a juneberry will flower synchronously (at the same time).

However, the resulting fruits develop asynchronously (at different times), so it’s difficult to gather a large harvest of juneberries in a single day. Because only a few fruits ripen at a time, it’s easy for a bird or two to strip the bush empty: to ensure a large harvest, John recommends covering the shrub with netting.

The other white-flowered shrubs carpeting the forest right now are plums. They are more flower than leaf right now and tend to grow in thickets. (Juneberries tend to grow singly.)

John states, “You can kind of walk around in a juneberry forest, but you can’t walk around in a plum thicket. It’s just too dense.”

More Phenology

A closer look at the shrub schedule

Canada fly honeysuckle with leaves and flowers. The image shows a twig with green leaves and a pair of small yellow flowers. the leaves are oval-shaped, about two inches long, and look soft. The flowers share a stem, which splits in two at the base of the flowers. The flowers are trumpet-shaped and are a pale yellow color. the image is captioned "Canada fly honeysuckle".
iNaturalist user sophiamunoz
Canada fly honeysuckle with leaves and flowers.

Pin cherries and chokecherries will come later in the season. John predicts the pin cherries will bloom in about four to five days, and the choke cherries later than that. The rough order of flowering shrubs is as follows:

  1. Juneberries 
  2. Plums 
  3. Pin cherries 
  4. Chokecherries (and nannyberry and black chokecherry) 

Other flowering shrubs include the Canada fly honeysuckle (which has twinned trumpet-shaped yellow flowers and is at peak bloom in Grand Rapids), leatherwood (which has finished flowering), and leather leaf (a swamp plant with white flowers arranged in rows along the sweeping branches: it is currently blooming).

Spring ephemerals and associates

In the forb layer, blueberries, sessile bellwort, large-flowered bellwort, white violets and sand violets are blooming in the Grand Rapids area. Trilliums, swamp red currants, dwarf raspberries and red elderberries are on the verge of blooming, and cowslips are just starting to flower. Trailing arbutus is wrapping up its flowering season. Bloodroot finished flowering. Columbine is up.

The ferns (e.g. interrupted fern, ostrich fern, lady fern and bracken fern) are all up, along with horsetails (e.g. field equisetum, meadow equisetum, and forest equisetum).

A wood frog sits on a piece of bark. It is a small frog with a white lip, a dark stripe running from its nostril through its eye, and a light brown body.
A wood frog sits on a piece of bark.

Winged things and wood frogs

The spring bird parade continues at a rapid pace! Orioles and hummingbirds have returned. Turkeys are gobbling, grouse are drumming, and the morning chorus is verging on deafening.

Much to John’s dismay, they brought with them mosquitoes, wood ticks and deer ticks. John describes them as “fierce and plentiful,” and reminds us to check carefully after venturing outside.

While listening to the spring frog calls, John noticed a distinct lack of wood frogs this year. He’s heard spring peepers and chorus frogs in good numbers, but only a few wood frogs. He’d be interested to hear if you’ve noticed a similar (or different) pattern! Please let him know.

That does it for this week! For more phenology, subscribe to our Season Watch Newsletter or visit the Season Watch Facebook page.

Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).

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Charlie Mitchell (she/they) joined the KAXE team in February of 2022. Charlie creates the Season Watch Newsletter, writes segment summaries for the website, and coordinates our Engaging Minnesotans with Phenology project. With a background in wildlife biology, she enjoys learning a little bit about everything, whether it's plants, mushrooms, aquatic invertebrates, or the short-tailed shrew (did you know they can echolocate?).