Category Archives: Phenology

Seen Last Week

Goldenseal, 20 April 2026 (photo by Kate St. John)

26 April 2026

Hatch Day preempted Saturday’s usual Seen This Week, so today we’ll take a look at Spring in photos Seen Last Week.

  • Raccoon Creek State Park
    • Goldenseal
    • Maidenhair fern
    • Dwarf larkspur
  • Frick Park: Golden ragwort
  • Schenley Park
    • Fleabane, an alien with pretty pink accents
    • Fringetree
    • Jack in the pulpit — from the top and under the spathe
Maidenhair fern, 20 April 2026 (photo by Kate St. John)
Dwarf larkspur, Racoon Creek Wildflower Preserve, 20 April 2026 (photo by Kate St. John)
Golden ragwort, Frick Park, 18 April 2026 (photo by Kate St. John)
Fleabane in bloom, Schenley Park, 22 April 2026 (photo by Kate St. John)
Fringetree in bloom, Schenley Park, 22 April 2026 (photo by Kate St. John)
Jack-in-the-pulpit with a look inside, Schenley Park, 22 April 2026 (photo by Kate St. John)

Aphids were all over this plant ten days ago in Schenley Park … but then it got cold and they died.

Aphids did not survive the almost-freeze in Schenley Park, 22 April 2026 (photo by Kate St. John)

On a trail in Frick Park I encountered the enormous root ball of a blow down. For perspective I propped my walking stick against it. Note the black hand loop and orange uppershaft. The root ball is a lot taller than me.

Root ball of a blown down tree in Frick Park. Walking stick shows perspective, 19 April 2026 (photo by Kate St. John)

Irritants Are Growing

Poison ivy! New leaves are shiny, older leaves are not, Frick Park, 19 April 2026 (photo by Kate St. John)

23 April 2026

Irritants? Yes there are many, but I’m talking about plants.

Despite our highly variable weather, some very irritating plants are growing well. Last Sunday, 19 April, I found poison ivy boasting an assortment of new and mature leaves. Just a week earlier, all its leaves were new.

Poison ivy! New leaves in Frick Park, 12 April 2026 (photo by Kate St. John)

Some people say you can recognize poison ivy by its shiny leaves but as you can see only the new leaves are truly shiny. The older leaves have a matte finish.

Learn more about irritating plants that get a head start on making your skin itch in this vintage article from 2019.

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Seen This Week: Flowers, Leaves & Urban Wildlife

18 April 2026

Seen this week. All photos are my own.

Lilacs blooming in the city, 14 April 2026 (photo by Kate St. John)

Urban Wildlife: Here’s what I saw, literally outside my window, in 10 minutes on Thursday 16 April.

That dot on Central Catholic High School’s cross is a red-tailed hawk. A pair is nesting within sight of the cross … but where?

Red-tailed hawk on Central Catholic cross, 16 April 2026 (photo by Kate St. John)

Three deer crossed the street outside my window and grazed next to the sidewalk as cars drove by. When people approached on the sidewalk and started taking pictures and video, the deer walked away.

Three deer browsing on Ascension Church lawn, 16 April 2026 (photo by Kate St. John)

How urban is their habitat? Very urban.

Where the deer were browsing on Ascension Church lawn, 16 April 2026 (photo by Kate St. John)

Seen This Week: More Flowers and Leaves

Henbit blooming along Nine Mile Run Trail, Frick Park, 5 April 2026 (photo by Kate St. John)

11 April 2026

Despite temperatures that dipped into the upper 20s on Wednesday, spring is still making progress in Pittsburgh. This week I found more flowers and leaves.

Though they don’t look like flowers these yellow-orange structures are the inflorescence of bear corn (Conopholis americana, formerly squaw root), a underground non-photosynthesizing plant that is parasitic on beech and oak roots. The literature officially says “oak roots” but I always find bear corn under beech trees.

Bear corn in Schenley Park, 10 April 2026 (photo by Kate St. John)

The pawpaw trees (Asimina triloba) are blooming in Schenley Park. Their dark brown flowers have a faintly stinky smell to attract flies and beetles as pollinators. Pawpaw’s success is a good sign for zebra swallowtails (Eurytides marcellus). It is their only host plant.

Pawpaw flowers, Schenley Park, 10 April 2026 (photo by Kate St. John)

This week I finally noticed that the flowers on henbit (Lamium amplexicaule) and purple dead-nettle (Lamium purpureum) are nearly the same unusual shape — like the mouth of a tiny cave with a double landing pad at the opening. Duh! Of course they are similar. Both are in the Lamium genus, native to Eurasia.

In a patch of flowers along the Nine Mile Run Trail I found both plants in close proximity. The first photo has henbit in focus, the second focuses on purple dead-nettle so you can compare them.

Henbit (and purple dead-nettle) blooming along Nine Mile Run Trail, 5 April 2026 (photo by Kate St. John)
(Henbit and) Purple dead-nettle blooming along Nine Mile Run Trail, 5 April 2026 (photo by Kate St. John)

Jetbead (Rhodotypos scandens) has both flowers and leaves this week. Native to China and Japan it was planted in Schenley Park as an ornamental. Unfortunately it is invasive.

Jetbead in bloom, Schenley Park, 10 April 2026 (photo by Kate St. John)

Ohio buckeyes (Aesculus glabra) in Schenley Park have gone from merely leaves to blooming flowers in just one week. This tree had mild frost damage. If you look closely you’ll see a few dark green, shriveled leaves.

Ohio buckeye in bloom, Schenley Park, 8 April 2026 (photo by Kate St. John)

And yet, despite all the greenery the woods are still mostly bare. Sunlight reached the forest floor yesterday prompting woodland wildflowers to bloom.

Shadows and pale green leaves, Schenley Park, 10 April 2026 (photo by Kate St. John)

By 5 May all the trees will be leafed out and the spring wildflowers will have gone to seed.

An Easter Trout Lily

Trout lily at Fall Run Park, Glenshaw, 4 April 2026 (photo by Kate St. John)

Easter Day, 5 April 2026

This native lily is blooming today at Fall Run Park in Glenshaw, PA. I found it yesterday while looking for Louisiana warblers (Parkesia motacilla), whom we heard but never saw.

Trout lilies (Erythronium americanum) grow from 1/2″ to 1″ oval underground corms buried very deeply compared to other lily family plants. I believe the depth is an advantage for those that grow in a flood plain that washes away or fills with silt after a flood. For instance, at Raccoon Creek Wildflower Reserve.

When you find one trout lily you usually find many because they grow in colonies. Some trout lily colonies are as much as 300 years old. Individuals in a colony often reproduce asexually from small bulbs budding off of the main corm or via a tubular fleshy stem called a “dropper.”

The trout lily’s name comes from its “gray-green leaves, mottled with brown or gray, which allegedly resemble the coloring of brook trout.”

Brook trout caught and released (photo from Wikimedia) (*)

I used to think the flower partly got its name because it always blooms during trout season in Pennsylvania. (Trout season opened yesterday at 8:00am.)

Note: Most of this article is paraphrased from the Wikipedia article on trout lily.

Seen This Week: Greening Up

Virginia bluebells in Schenley Park, 3 April 2026 (photo by Kate St. John)

4 April 2026

Woodlots in the City are greening up with the first tentative leaves …

Schenley Park is greening up, 31 March 2026 (photo by Kate St. John)

… and full leaf on the Ohio buckeyes in Schenley Park.

Ohio buckeyes are the first to leaf out in Schenley Park, 3 April 2026 (photo by Kate St. John)

New flowers bloomed in the summer-like heat: Virginia bluebells near the Visitors Center and a star magnolia near the Westinghouse memorial.

The star magnolia’s flowers were in bud during the mid March freeze so it recovered well. Unfortunately, the forecast for Tuesday night, 7 April, calls for a low of 27ยฐF. ๐Ÿ™

Star magnolia at Schenley Park, 31 March 2026 (photo by Kate St. John)

Invasive garlic mustard leafed out on 15 March and was blooming this Friday.

Garlic mustard on 15 March and 3 April (photo by Kate St. John)

Coltsfoot went from flowers in snow on 19 March to full bloom on 3 April.

The photo below shows how many trees are greening up near the Panther Hollow Bridge which is covered in tarps for the current rehab.

What you can’t see is the female American robin carrying mud and grasses in her beak. She’s building a nest that she believes will be very safe, inside the tarp in the construction zone. The gap lets her in. Maybe the nest will be very safe. Maybe it’s a bad idea. She’ll find out.

Greening trees and a gap in the tarp at the Panther Hollow Bridge, 3 April 2026 (photo by Kate St. John)

And finally, more evidence of a bird that’s not in the photo. These track lines are small holes drilled by yellow-bellied sapsuckers. The tree heals the holes by growing more bark. Sapsuckers only visit Schenley Park on migration. I saw two yesterday.

Yellow-bellied sapsucker holes in a hickory, 31 March 2026 (photo by Kate St. John)

Seen This Week: Frost Damage, Brave Flowers and a Few Leaves

Northern magnolia flower before and after frost: 17 and 26 March 2026 (photo by Kate St. John)

28 March 2026

A week ago I posted a photo of a northern magnolia flower with snow (top left). This week that same flower and all the others on the tree are brown and shriveled from frost damage (top right).

After it warmed up (again) this week brave tulips bloomed along Fifth Avenue in Oakland. They’re brave to chance another frost and brave to chance being eaten by deer. Yes, deer on Fifth Avenue near the Cathedral of Learning. I’ve seen them cross from Clapp Hall to the Heinz Chapel side. to munch on treats like these. Looks like one of these plants in the background was eaten before it bloomed. Hmmm!

Tulips blooming along Fifth Ave in Oakland, 26 March 2026 (photo by Kate St. John)

Our native trees are cautious but the aliens are leafing out: Viburnum plicatum at Frick Park and Amur honeysuckle just about everywhere.

Invasive Viburnum plicatum puts out new leaves, Frick Park, 22 March 2026 (photo by Kate St. John)
Amur honeysuckle leaves, Frick Park, 22 March 2026 (photo by Kate St. John)

Also This Week: On the night of Thursday-Friday 26-27 March, 2.10+ inches of rain fell in the Raccoon Creek watershed. On Friday morning Friends of Raccoon Creek State Park visited the area and posted the resulting flood at Raccoon Creek Wildflower Reserve here on Facebook. The wildflowers had just begun to bloom but they’re under mud and water now. When the water recedes a few will bloom late. The rest won’t recover until next year. Alas! I was going to go see the flowers this coming week.

Seen This Week: Snow, Flowers and Mud Season

Northern magnolia with snow, 17 March 2026 (photo by Kate St. John)

21 March 2026

The weather has been a yo-yo this week with a sunny high of 68ยฐF on Sunday and 60ยฐF on Monday. Then it started snowing hard at 6:00pm Monday. Three inches covered the City while at Pittsburgh’s weather station the snow was twice as deep. It set a new record for a yo-yo day.

After the snow stopped, ragged clouds raced across the sky at 10:30pm, 16 March.

After the snow stopped, ragged clouds, 16 March 2026 (photo by Kate St. John)

The next morning the sky was clear (see the meteor blog) and the snow began to melt. Dippy still wore a snow cloak at 10:50am.

Snow on Dippy, 17 March 2026 (photo by Kate St. John)

Damage to northern magnolia flowers (photo at top) and red maples became evident.

Damaged red maple flowers in Pittsburgh, 17 March 2026 (photo by Kate St. John)

But soon the sun had warmed the ground so much that steam rose from the mulch outside Carnegie Museum.

video by Kate St. John

Two days later it was again cold in the morning when four of us walked the Muddy Creek Trail at Moraine State Park. By noon it warmed up considerably. We found skunk cabbage and coltsfoot poking up through the snow.

Skunk cabbage at Muddy Creek Trail, Moraine State Park, 19 March 2026 (photo by Kate St. John)
Coltsfoot beginning to open at Moraine State Park, 19 March 2026 (photo by Kate St. John)

And we found out that it is Mud Season! … Melissa’s beagle, Henry, is keeping his paws clean.

Mud Season at Moraine State Park. Henry waits for us to continue walking, 19 March 2026 (photo by Kate St. John)

March is supposed to come in like a lion and go out like a lamb. This week we saw lamb, lion, lamb.

Seen This Week: Buds Swell and Open

Honeysuckle from buds to first leaves, Schenley, March 8 & 13 (photos by Kate St. John)

14 March 2026

It was as hot as May at the beginning of the week as leaf and flower buds swelled and opened. Then temperatures returned to normal and it felt cold. Seen this week were ….

The first Amur honeysuckle leaves (above) and Cornelian cherry tree flowers.

Cornelian cherry flowers: buds to fully open, Schenley, March 6 to 11, (photos by Kate St. John)

Swelling buds on ginkgo trees.

Ginkgo tree buds swelling, Schenley, 13 Mar 2026 (photo by Kate St. John)

Invasive Callery pear about to bloom.

Callery pear flowers buds swell, Schenley, 13 Mar 2026 (photo by Kate St. John)

Viburnum plicatum leaf buds swelling in Frick Park. (This shrub is invasive.)

Virburnum plicatum leaf buds, Frick, 8 Mar 2026 (photo by Kate St. John)

First flowers on forsythia.

Forsythia drooping after cold night, Schenley, 13 Mar 2026 (photo by Kate St. John)

Pale green branches on the willows … tiny leaves.

Willows turning green in Schenley Park, 12 Mar 2026 (photo by Kate St. John)

First goutweed leaves.

First goutweed leaves, Schenley, 11 Mar 2026 (photo by Kate St. John)

And tree pollen allergies if you are susceptible. My husband wondered why his allergies gave him a twinge this week. American elm flowers were blooming. They are wind-pollinated.

Pixel Weather screenshot, Pollen count, 10 Mar 2026

All the tender leaves and flowers will be smacked down this coming Tuesday and Wednesday when temperatures drop into the low 20s. I cannot feel bad for half of the plants pictured here. Four of them are invasive aliens.

Expecting Spring: Then and Now

Snowdrops photo by Kate St. John | Red-winged blackbird photo from Wikimedia

12 March 2026

Phenology is the study of the times when natural phenomena recur throughout the year. 

At the beginning of this century, before the Internet was so accessible, Chuck Tague wrote a bi-monthly paper newsletter called The Nature Observer News that listed outings, nature club meetings, and what to expect outdoors in the upcoming half of the month.

In 2008-2009 I collaborated with Chuck to post a phenology for Western Pennsylvania based on his articles in The Nature Observer News. He created the lists about 20 years ago from his observations at the time.  Since then our climate has gotten warmer and some nature events occur earlier than they used to, enough to jog them a half-month.

Thinking about what you’ve seen in recent weeks, have any of these nature events moved backward to a prior half-month? Are they all on time this spring?

I’ve marked the differences I’ve seen with an (X) and descriptions at the end.

Maple trees with sugar pails (photo from Wikimedia Commons)
Maple trees with sugar pails (photo from Wikimedia Commons)

Phenology (20 years ago) for LATE FEBRUARY


Common grackles and red-winged blackbirds flock (photo by Nancy Magnusson via Flicker Creative Commons license)

Phenology (20 years ago) for EARLY MARCH

  • Noisy flocks of red-winged blackbirds.
  • First of the Year common grackles. (X)
  • Large flocks of robins sing at dusk and dawn for about two weeks.
  • Intensive peregrine falcon courtship.
  • First flowers in gardens: Snowdrops, crocuses, forsythia (X)
  • Mud Season: switch from snow boots to mud boots.
  • Jacket Weather (instead of the winter coats) (X)

Coltsfoot at Barking Slopes, 25 March 2025 (photo by Kate St. John)

Phenology (20 years ago) for LATE MARCH

  • Migrating ducks, geese and tundra swans on local lakes. (X)
  • Tree swallows, eastern phoebes and eastern bluebirds arrive.
  • Garden flowers and trees: Daffodils, tulips, ornamental cherry.
  • Woodland flowers: coltsfoot, harbinger of spring, snow trillium
  • Skunks and groundhogs are getting active
  • Peregrine falcons lay eggs and begin incubation.
  • American woodcocks โ€œpeentโ€ and twitter in their aerial mating dance.  (X)
  • Spring peepers and wood frogs are singing and mating. (X)

Changing Expectations of Spring: Then and Now

Here are the discrepancies I’ve seen in the past few weeks.

  • I saw a turkey vulture on 10 February at Emsworth Dam. This was a half-month early but I didn’t think much about it because I thought they stayed in that area of the Ohio River all winter.
  • First of the Year common grackles came back in late February. They did not wait for early March.
  • Jennifer Zimmerman commented that the first sighting this year of crocus in my Moon Twp yard was 2/21 and several bees on the crocus 2/28. Crocuses were early by a half month.
  • We skipped Jacket Weather for summer clothes on 7 March when the high went up to 78ยฐF.
  • Migrating ducks and tundra swans arrived at Yellow Creek State Park on 28 Feb and in the first week of March. Moraine State Park had waterfowl on 1 March.
  • American woodcocks were here doing their sky dance in early March. However they dance for at least a month so it may be that the phenology is pointing out their later dances.
  • Spring peepers and wood frogs began singing in early March (as reported by friends). They did not wait until the second half of the month.