American sycamore seed ball disintegrating at the end of winter (photo from Wikimedia Commons)
22 March 2025
As the weather warmed this month American sycamore (Platanus occidentalis) seed balls disintegrated to disperse their wind-driven seeds.
On 16 March it was very windy when I visited Herr’s Island back channel. Sycamore achenes (seed packets) blew by me in the wind and piled up in the cracks like snow drifts.
A single American sycamore seed, 16 March 2025 (photo by Kate St. John)
Sycamore snow.
Many sycamore seeds gathering like snow drifts, Herr’s Island, 16 March 2025 (photo by Kate St. John)
They had come from seed balls like these that had waited all winter for spring heat to make them stretch and burst.
Sycamore seed balls hanging like ornaments, 3 March 2018 (photo by Kate St.John)
Not only do they disperse on the wind but the fluff-tops have a second mode of transportation. They float.
Sycamore seeds swirling in the Allegheny River in Herr’s Island back channel, 16 March 2025 (video by Kate St. John)
Water carries them to their favorite habitats.
American sycamore is found most commonly in bottomland or floodplain areas, thriving in the wet environments provided by rivers, streams, or abundant groundwater.
Golderod in winter, Beechwood Farms, 3 March 2025 (photo by Kate St. John)
8 March 2025
During this week’s brief and gorgeous warm weather I thought it was spring and took photos of interesting plants at Beechwood Farms. Back home I see that they are wintry weeds and trees with only a hint of what is to come.
Goldenrod, above, has not yet released its fluffy seeds to the wind.
I was fascinated by the yellow bark on these maple-family twigs. Is it box elder …?
Whose bud is this? Beechwood farms on 3 March 2025 (photo by Kate St. John)
Yes. The yellow bark threw me off but the opposite buds and green bark on older branches are both traits of box elder (Acer negundo).
What species is this small tree? Beechwood Farms on 3 March 2025 (photo by Kate St. John)
The mystery leaves, below, required my plant identification tool but the answer was unsatisfying and probably wrong. Dame’s rocket (Hesperis matronalis)? I doubt Beechwood would have left such an invasive plant in place.
New leaves at Beechwood Farms on 3 March 2025 (photo by Kate St. John)
However, the tool pointed me to a video about eating Dame’s rocket (Hesperis matronalis) in the spring. Great idea! This plant is invasive. (In the video it is called wild phlox. Maybe a Canadian common name for it.)
Traditional bucket collecting maple sap for sugaring at Beechwood Farms, 3 March 2025 (photo by Kate At. John)
4 March 2025
This winter we’ve hated the cold weather but the freezing temperatures have been good for maple sugaring in March. Cold as it was, this winter was closer to what we had before climate change and the maples in Pittsburgh are happy about it.
Maple sap runs best when daytime temperatures are above freezing and nights are below freezing. When the nights don’t freeze the sap stops running, and the season is over. Last year the season ended early because it was so hot.
Audubon Society of Western Pennsylvania (ASWP) has used three methods to collect sap from sugar maples at several of their properties: traditional buckets, bags, and tubes. Yesterday at Beechwood Farms I could tell the sap was running because the bags were filling up.
Bag collecting maple sap at Beechwood Farms, 3 March 2025 (photo by Kate At. John)Tubes collecting maple sap at Beechwood Farms, 3 March 2025 (photo by Kate At. John)
All told, it takes 40 gallons of sap to make just about 1 gallon of syrup. The sap, which is 2% sugar and 98% water, tastes like lightly sweetened water, tasty and refreshing, but lacking in flavor. The boiling process reduces the liquid until the concentration is 65% sugar.
Maple for Scouts. at Beechwood Farms 3/8/2025, Succop 3/15, and Buffalo Creek Nature Park in Sarver 3/22
Hike Through Maple History: Maple Madness. at Beechwood Farms 3/15/2025 and 3/22
Sweetest Season
Maple Drink Tasting, Adults Only Happy Hours: Maple Madness. at Buffalo Creek Nature Park 3/6/2025 and 3/13
Sap collection will end when the maple buds open. (The festivities will continue with pre-collected sap.)
How can you tell that maple buds have opened? From the ground the twigs look thick with little lumps. This red maple was already flowering at Beechwood. Fortunately it’s not the species that produces good sap.
Red maple is flowering already at Beechwood Farms, 3 March 2025 (photo by Kate St. John)
Extensive winter damage frost crack in a black cherry tree, Hays Woods, 2 Feb 2024 (photo by Linda Roth)
9 February 2025
On a walk in Hays Woods on 2 February, Linda Roth and fellow hikers found a few severely damaged trees with long vertical cracks in their bark and trunks. What made the trees split like this?
Extensive winter damage frost crack in a black cherry tree, Hays Woods, 2 Feb 2024 (photo by Linda Roth)
One of the most common reasons for cracks and splits on tree trunks is cold temperature. Frost cracks are caused when the inner and outer wood in the tree’s trunk expands and contracts at different rates when temperatures change. This happens when winter temperatures plummet below zero especially after a sunny day when a tree’s trunk has been warmed by the sun. The different expansion rates between the inner and outer wood can cause such a strain on the trunk that a crack develops.
January’s weather was extreme enough to cause the damage. It was 43°F on the 18th, then plummeted below zero a few days later.
Frost cracks occur suddenly, can be several feet long, and are often accompanied by a loud rifle shot sound. They often originate at a point where the trunk has been physically injured in the past. Maples and sycamores are the most prone to frost cracks. Apples, ornamental crabapple, ash, beech, horse chestnut and tulip tree are also susceptible. Isolated trees and trees growing on poorly drained soils are particularly prone to frost cracks.
You know it’s cold when the trees crack and explode. According to Wikipedia, the Sioux and Cree called the first full moon of January “The moon of cold-exploding trees.”
Christmas tree Before and After — decorated and discarded (photos from Wikimedia Commons)
31 December 2024
It’s just about time to take down the Christmas tree. If you have a backyard, and especially if you have bird feeders, save your old tree for the birds.
Backyards without vegetation near the bird feeders have no safe place to hide. The feeders attract bird predators but the birds can’t fly fast enough to reach distant safety.
And if you don’t have a backyard or a bird feeder, there are useful ways to dispose of your Christmas tree in the City of Pittsburgh and surrounding areas.
How long did it take to become a Christmas tree? According to the National Christmas Tree Association, “it can take as many as 15 years to grow a Christmas tree of typical height (6 – 7 feet) or as little as 4 years, but the average growing time is 7 years.”
From seed to sapling here’s what it might have looked like during its first two years.
The time lapse shows a stone pine (Pinus pinea) which is unlikely to become a Christmas tree. Native to the Mediterranean, they have been planted around the world.
I probably saw them in Spain without knowing their significance. I imagine they are the trees in the background of my photo of the “Shade Horse” at Parque Natural de Los Alcornocales, Spain last September.
The Shade Horse and his sheep companion at Parque Natural de Los Alcornocales, Spain, 13 Sept 2024 (photo by Kate St. John)
Rose blooming in November, 23 Nov 2024 (photo by Kate St. John)
30 November 2024
Even though it’s November and getting colder and darker by the day, I found some confused flowers this week. Imported trees and plants that should be dormant were in bloom.
A rose, above, and an ornamental cherry tree were beautiful in the rain.
Ornamental cherry tree blooming in November, 23 Nov 2024 (photo by Kate St. John)
Moth mullein was battered but blooming on an almost sunny day.
Battered but blooming, moth mullein in November, 23 Nov 2024 (photo by Kate St. John)
Northern magnolia buds were swelling in anticipation of spring … even though it was late November.
Fat buds on northern magnolia, 27 Nov 2024 (photo by Kate St. John)
Alas, these flowers will be no match for this week’s (finally normal) freezing temperatures.
November is a good time of year to look for hackberry trees in Pittsburgh and examine their fallen fruit. By now the pulp has worn off the pits, but unlike wooden cherry pits hackberries’ are like white seashells with a microscopic lattice of opal inside.
Common hackberry pits: one whole, one opened (photo by Kate St. John)
Learn about these amazing structures in this vintage article.
Then go find a hackberry tree (and an electron microscope).
Hackberry bark and bare branches make it easy to identify the tree, even in winter. The bark has ridges and the ridges have growth lines.
Hackberry bark has ridges. The ridges have growth lines (photo by Kate St. John)
Up in the bare branches, hackberry trees sometimes have twig formations called witches brooms “produced by the effects of an eriophyid mite (Aceria celtis) and/or an associated powdery mildew producing fungus (Sphaerotheca phytoptophila)” — from bugwood.
“Monkey balls” = fruit of osage orange tree, Schenley Park, 20 Nov 2024 (photo by Kate St. John)
23 November 2024
Now that the leaves have fallen fruits and seeds are prominent in the landscape.
Osage orange (Maclura pomifera) trees have prolific fruit this fall but nothing eats the “monkey balls” so they just lay on the ground to rot. If you crack one open it has sticky latex inside. Who would eat this fruit? The answer is in the video at the end!
The fruiting body of a shaggy mane mushroom (Coprinus comatus) poked up among the leaf litter near Five Points at Moraine State Park.
Fruiting body of Shaggy Mane mushroom, Moraine State Park near Five Points, 18 Nov 2024 (photo by Kate St. John)
Red fruits of oriental bittersweet (Celastrus orbiculatus) are a favorite food of migrating American robin, protected by a hard yellow-orange skin that pops off in sections. It looks like a squirrel gnawed off this branch and lost his meal.
Fruit of oriental bittersweet, 18 Nov 2024 (photo by Kate St. John)
Late boneset has gone to seed in Schenley Park.
Late boneset seeds surrounded by fluff, Schenley Park, 20 Nov 2024 (photo by Kate St. John)
Just a few trees still have leaves. I found this colorful sweetgum along a sidewalk at CMU. Someone ripped a piece off the yellow leaf.
Colorful leaves on sweetgum, 20 Nov 2024 (photo by Kate St. John)
Female spicebush with berries, 25 Sept 2017 (photo by Kate St. John)
21 November 2024
In the garden we often grow “perfect” flowers such as roses, lilies and tulips with male and female parts in every flower. However, many woody shrubs and trees have single sex flowers. Some species grow both sexes on the same tree, others have only one sex on an entire plant. And so, some plants are simply female.
Monoecious species have both flower sexes on the same plant. Examples include hickory and pecan trees, cucumbers and pumpkins, cherries, common grape vine and corn (maize).
Dioecious plants produce only male or female flowers on individual plants and only the female plants produce fruit. Examples include gingkos (stinky fruit from female trees!) …
