Sunrise in Pittsburgh, 19 October 2025 (photo by Kate St. John)
25 October 2025
Vibrant reds and oranges graced the sky and the forest in Pittsburgh this week.
Our region is in the midst of an oak-hickory forest so red-colored leaves can be scarce. Oaks turn dark red after most other trees are bare and hickories turn yellow, so I look forward to the moment when our few sugar maples turn red. It happened this week in Schenley Park, as you can see below.
Fall color on maples in Schenley Park, 23 Oct 2025 (photo by Kate St. John)Fall color on maples in Schenley Park, 23 Oct 2025 (photo by Kate St. John)Fall color along the Lower Trail at Schenley Park. Notice that it’s yellow. 20 Oct 2025 (photo by Kate St. John)Fall color on maples in Schenley Park, 23 Oct 2025 (photo by Kate St. John)Sunlight breaks through the background; fall color in Schenley Park, 23 Oct 2025 (photo by Kate St. John)
Two deer browsed near Schenley’s Upper Trail. One is already in her gray winter coat but so close to the trail that her camouflage didn’t matter. I would have missed the other deer (yellow arrow) except that it moved.
Two deer browsing in Schenley Park near the Upper Trail, 20 Oct 2025 (photo by Kate St. John)
Cold temperatures have ended this year’s spotted lanternflies so I was surprised to see one on the Panther Hollow Bridge. The air was so cold that didn’t move as I approached. Hah! I see you.
Spotted lanternfly, Schenley Park, 20 Oct 2025 (photo by Kate St. John)
p.s. Mary Kate reminded me that sweetgum trees are very pretty in the fall. I’ll try to get some pictures this coming week.
This week I learned from a bow hunter that the few deer I see resting in Schenley Park are too young to hunt. Restrictions on antler size and “plumage” (coat indications) prohibit taking the ones I’ve seen. Apparently these individuals somehow know they are safe.
After four weeks of browsing neighborhood yards the pickings must be slim over in Shadyside. On Saturday 11 October a doe visited the Oakland highrise district to browse on the landscaping, slideshow above.
Burr oak acorns, Flagstaff Hill, Schenley Park, 17 September 2025 (photo by Kate St. John)
20 September 2025
There are so many oaks in Schenley Park that a few burr oaks (Quercus macrocarpa) are not noticeable until they drop their large, fringed acorns. Where did they come from? I looked up to find the tree, taller and broader than its neighbors.
Burr oak acorn, Flagstaff Hill, Schenley Park, 17 September 2025 (photo by Kate St. John)
The burr oak’s location does not have a good view so I sat beneath a large oak at the top of Flagstaff Hill overlooking Oakland. Based on acorns, leaves, and the history of landscaping in Schenley Park, my guess is that I sat beneath an English oak (Quercus robur).
(presumably) English oak acorns, Flagstaff Hill, Schenley Park, 17 September 2025 (photo by Kate St. John)
It’s a high mast year for this particular tree. The only way I avoided being hit by acorns was to sit with my back against the trunk!
Other sightings this week include birds Tuesday morning at Bird Lab’s Hays Woods banding which I wrote about on Wednesday’s blog: Hays Woods Birds Live up to Expectations.
Common yellowthroat at Hays Woods Bird Lab, 16 September 2025 (photo by Kate St. John)Dotted line across the morning sky, Pittsburgh 17 Sept 2025 (photo by Kate St. John)
I rarely walk through the Heinz Chapel Memorial Garden but its fountain is attractive during the drought. On the way to the fountain I found an engraved paver stone with a non-traditional dedication.
Memorialized paver stone at Heinz Chapel, Univ of Pittsburgh, 17 Sept 2025 (photo by Kate St. John)
If you want to find this stone, enter the Heinz Memorial Chapel Garden from the Bellefield Avenue side (near the steps to Bellefield Ave) and look at the pavers along the left. (This photo does not include a view of the Will You Marry Me paver.)
While last week’s heat wave broke here on Friday, I was in Virginia where the heat persisted and was even more intense. The temperature got up to 99° in Virginia Beach with a heat index somewhere near 110°F. I don’t remember the number. I stayed indoors. Meanwhile all the plants and animals were stuck outside in adverse conditions but one ornamental tree was thriving. Crape myrtle loves heat.
Crape myrtle (Lagerstroemia sp., also spelled crepe myrtle) is a small ornamental tree or shrub from Asia and the Indian subcontinent that is widely planted in southeastern Virginia. There are many species and many varieties bred for color and local conditions.
The trees that thrive in Virginia Beach are not the same variety that survives in Pittsburgh. Pittsburgh is too cold for typical crape myrtle so we have to plant cold tolerant varieties. I hear they were slow to bloom during our cold spring.
Thirteen years ago I marveled at crape myrtle’s resilience as I melted in the Virginia heat. Learn more in this vintage article.
Crape myrtle, Smithfield, VA, 7 July 2012 (photo by Kate St. John)
Woody vine embraces a tree branch, Raccoon Wildflower Reserve, 26 May 2025 (photo by Kate St. John)
2 June 2025
Animals embrace and release but when plants wrap around each other the result is often permanent. Sometimes an embrace is intentional, sometimes not.
Intentional
Almost like a snake, the woody vine pictured at top intentionally wrapped itself around a tree branch. But then it stopped growing and left the two locked in a vegetative embrace.
Dodder (Cuscata), pictured below, is a parasitic native annual in the morning glory (Convolvulaceae) family that intentionally wraps itself closely around a plant stem. It then inserts very tiny feelers between the cells and sucks nutrients from its host. As an annual, it starts growing from seed but loses its soil-based roots when it has found a really good host.
Dodder more-than-embracing another plant, June 2017 (photo by Kate St. John)
Porcelain berry (Ampelopsis glandulosa) and grapevine intentionally drape themselves on trees and shrubs to lift themselves above the canopy. When this vine fell it embraced the oak.
Fallen vine embraces the oak it fell from, Moraine State Park, October 2022 (photo by Kate St. John)
Some plants have leaves that clasp the stem, circled in pink below. Botanists: Can you tell me the name of this plant? I forgot to note it when I took the photo at Raccoon Wildflower Reserve.
Alternate leaves clasp the stem, Raccoon Wildflower Reserve, 26 May 2025 (photo by Kate St. John)
Unplanned, Inadvertent
There are also inadvertent vegetative embraces, some of which are temporary.
Two trunks of the same species grew so close together that they fused at the base in this permanent embrace.
Two trees growing in a close embrace, January 2010 (photo by Kate St. John)
When this skunk cabbage put up shoots in the spring, one of them speared a dead leaf whose ribs now prevent the skunk cabbage from opening. Temporary embrace? I like to rescue these plants, especially mayapple and trillium, by pulling off the dead leaf. I can’t remember if I rescued this one.
Dead leaf, speared by an emerging skunk cabbage leaf, prevents it from unfurling, April 2025 (photo by Kate St. John)
Woolly oak gall, Raccoon Wildflower Reserve, 25 May 2025 (photo by Kate St. John)
31 May 2025
Oak apple galls are shiny and brown so I was surprised to find this fuzzy one on a white oak stem. This not a fuzzy version of the oak apple gall. This is a woolly oak gall made by a completely different species of gall wasp (family Cynipidae).
Woolly oak galls are made by Callirhytis seminator, “the wool sower,” which places its galls only on white oaks and only in the spring.
The wasps are tiny, 1/8″ long, and have many predators including larger parasitic wasps. They do not sting humans.
Gall wasps have a two-generation alternating cycle: One generation produces stem galls, and the wasps that emerge from that stem gall mature and lay their own eggs in leaf galls. The wasps that emerge from the leaf gall mature and produce stem galls. Scientists do not know what the alternate wool sower wasp gall looks like.
Fallen red oak from 29 April storm, Falloon Trail Schenley Park, 20 May 2025 (photo by Kate St. John)
27 May 2025
On my walks through Schenley Park I am often curious about the demise of sturdy trees. Why did this intact red oak fall?
The simple answer is that it blew over during the 29 April wind storm as did so many other trees in Pittsburgh. But a closer look reveals a weakness that contributed to its demise.
Looking at the root ball, there are no obviously broken big roots that would have anchored the tree to the ground and it appears that the trunk is hollow. Something “ate” the tap and anchor roots. When a big wind came the tree fell over. My guess at the culprit is the fungus armillaria or honey mushrooms.
Weakness that made it fall: No long roots on root ball, 20 May 2025 (photo by Kate St. John)
Along the same trail I found this structurally compromised tree still standing. Only the bark, cambium and sapwood are holding it up.
Disintegrating red oak, Schenley Park, 20 May 2025 (photo by Kate St. John)
Inside, the trunk is hollowed out by major insect damage. Now that the exterior is cracked it won’t take much wind to knock the tree over.
Weakness causing disintegration: Hollowed from major insect damage, 20 May 2025 (photo by Kate St. John)
I’m always amazed when a tree snaps in the middle of the trunk. This black cherry fell over in May 2014 to reveal white sheets — armillaria — that weakened the tree.
Black cherry snapped in the middle, 30 May 2014 (photo by Kate St. John)
Read more about it in this Quiz+Answer from June 2014.
Fringetree in bloom, Schenley Park, 14 May 2025 (photo by Kate St. John)
17 May 2025
This week I went birding in three western Pennsylvania parks: Schenley Park in Pittsburgh, Moraine State Park in Butler County (halfway north) and Presque Isle State Park on the northern edge of PA. While there I noticed how plants showed the progress of spring from south to north.
Schenley Park has been at Full Leaf since 5 May so it’s hard to see the birds there. In the understory white fringetree (Chionanthus virginicus) hsa just gone past its blooming peak. Two “weedy” plants caught my attention, identified in the PictureThis app as slender woodsorrel (Oxalis dillenii a native species) and mouse ear chickweed (Cerastium fontanum) introduced from Europe.
Slender woodsorrel, Schenley Park, 14 May 2025 (photo by Kate St. John)Mouse ear chickweed, Schenley Park, 14 May 2025 (photo by Kate St. John)
For comparison, PictureThis identified this one found at Presque Isle as sticky mouse-ear chickweed (Cerastium glomeratum), also European.
Sticky chickweed, Presque Isle State Park, 15 May 2025 (photo by Kate St. John)
Though Schenley Park had already been at Full Leaf for six days on 11 May, oak leaves were just coming out at Moraine State Park.
New oak leaves, Moraine State Park, 11 May 2025 (photo by Kate St. John)
I found poison ivy (Toxicodendron rydbergii) leaves in all three parks. At Presque Isle the leaves were smaller and newer but still able to cause an itch. Poison ivy is getting big in Schenley Park on 14 May. Watch out!
Poison Ivy in Schenley Park, 14 May 2025 (photo by Kate St. John)
One week after Full Leaf, I saw this year’s first yellow poplar weevil* (Odontopus calceatus) clinging to my window. They usually swarm in June but last week was unusually hot.
Outside my window: First billbug of the year, 12 May 2025 (photo by Kate St. John)
(* Despite knowing better I can’t help but call these insects “billbugs” even though I know the name is wrong. Oy!)
Blue violets, 28 April 2025 (photo by Kate St. John)
3 May 2025
On Monday and before 5pm on Tuesday, spring was proceeding as normal though warm in Pittsburgh. I took photos of flowers and trees and leaves.
Blue violets
Pawpaw flowers and the beginnings of leaves
Red maple leaves and samaras.
Pawpaw flower, 2 May 2025 (photo by Kate St. John)Red maple leaves and samaras, 28 April 2025 (photo by Kate St. John)
Then on Tuesday just after 5:00pm a line storm with 71+ mph straight-line winds hit Pittsburgh and wiped out trees and power lines. Many trees were simply snapped off as those shown below in Schenley Park yesterday.
Who knew this oak was hollow? The wind took it apart on 29 April 2025, Schenley Park (photo by Kate St. John)Hemlock tree snapped off near Schenley Park Visitors’ Center on 29 April 2025 (photo by Kate St. John)
Pittsburgh Public Works started sawing their way into the park. The top of the hemlock was one of the first to cut as it was blocking the access road.
Top of the hemlock tree, cut by Public Works, Schenley Park, 2 May 2025 (photo by Kate St. John)
For an update on the damage, see this 24-minute video from CBS Pittsburgh. 24 minutes is a LONG time to watch so feel free to stop viewing at any time. The first 3 minutes give you the flavor of what it’s like. And as a for instance, three friends still don’t have power.
Since leaving Denver we’ve driven through some amazing scenery on our way to Gunnison, Colorado on Sunday night and Grand Junction on Monday. We crossed Monarch Pass, were awed by the Black Canyon of the Gunnison, and have passed through mountains, basins and valleys. Today we’ll spend part of our time in pinyon-juniper woodlands, nicknamed “PJ.”
Pinyon-juniper woodland dominates the slopes above the sagebrush and below the ponderosa pines in southern and western Colorado (quote from Colorado Birding Trail). To those of us from Pennsylvania this PJ woodland scene at Dominiguez-Escalante suggests an old field reverting to forest. Nope.
According to the Colorado State Forest Service, the most common PJ tree species are the Colorado piñon pine, the Utah juniper and the New Mexico or one-seed juniper (Juniperus monosperma) that thrive in drought-prone, cold areas where annual precipitation is 10-15 inches. The trees cope with these challenges by growing widely spaced and rarely exceeding 10 feet tall.
Colorado piñon pine (Pinus edulis) [or pinyon pine]
Pinyon jays (Gymnorhinus cyanocephalus) have such a symbiotic relationship with pinyon pines that these woodlands are really the only place to find them. Unfortunately the jay is declining dangerously and its disappearance could cause the pine to decline as well. In 2023 USFWS began a study to decide whether to list the pinyon jay as Endangered, described in the video below. As of this writing the jay’s status has not changed.
Though juniper titmice (Baeolophus ridgwayi) have “juniper” in their name they do not have the close relationship with junipers that the pinyon jay has with pines. This bird used to be the plain titmouse (he is definitely plain!) but was named for his preferred habitat when he was split from the oak titmouse in the 1990s. His “oak” cousin is well studied but he is not.
