Category Archives: Trees

Seen This Week: Winter Weeds and Trees

Trees, Winter Weeds & Trees
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.)

video embedded from EdibleWildFoods on YouTube

Speaking of edible plants, several parts of burdock are edible and the roots can be eaten year round.

Burdock in winter, Beechwood Farms, 3 March 2025 (photo by Kate St. John)

Dig it up and eat it. This plant is invasive. Read more before you dig –> Northern Woodlands Burdock: A Food That Will Really Grab You.

Cold Weather’s Been Good for Maple Syrup Season

Books & Events, Climate Change, Trees
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.

— PA Eats: Pennsylvania Maple Syrup

ASWP’s outdoor Maple Madness events will demonstrate how maple syrup is made.

Kids learn about maple sugaring (photo courtesy of Audubon Society of Western Pennsylvania)

To sign up for these events visit ASWP’s Program Listings website.

  • 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)

Cracks and Exploding Trees

Trees, Weather & Sky
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.

— Missouri Botanical Garden: WHat causes cracks and splits in tree trunks

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.

— Missouri Botanical Garden: WHat causes cracks and splits in tree trunks

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.”

But no one was out in Hays Woods on those extremely cold nights so no one heard the sound of exploding trees.

Keep Your Old Christmas Tree For The Birds

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.

Isolated backyard bird feeders. No cover for birds (photo from Wikimedia Commons)

Winter is especially difficult. There are no leaves to hide in so the birds are vulnerable to Coopers hawks and cats.

Coopers hawk spying a meal (photo from Wikimedia Commons)

By placing even one discarded Christmas tree near the feeder …

Discarded Christmas trees (photo from Wikimedia Commons)

… the hawk is foiled and can only wait for the birds to come out.

Coopers hawk eyeing a brush pile that’s full of birds (photo by Marcy Cunkelman)

For more information, see Utah Wildlife’s Don’t Toss your Christmas Tree.

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 Fast Does a Pine Tree Grow?

Trees
Scots pine at a tree farm (photo by Steven Katovich, Bugwood.org)

30 December 2024

Did you buy a live Christmas tree this year? If you live in Pennsylvania, chances are good that it grew at a local tree farm. PA ranks 4th among the top Christmas tree producing states.

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.

video embedded from Boxlapse on YouTube

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.

Stone pine forest at Huelva, Spain (photo from Wikimedia)
Stone pine foliage (photo from Wikimedia Commons)
Stone pine cones and seeds (photo from Wikimedia)

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)

Seen This Week: Confused Flowers

Phenology, Plants & Fungi, Trees
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.

Opal Inside

Trees, Winter Weeds & Trees
Common hackberry fruit (by Kate St. John) and precious opal (from Wikimedia Commons)

27 November 2024

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.

Tiny Opals

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.

Witches brooms on hackberry by Whitney Cranshaw, Colorado State University from Bugwood.org

Finding an electron microscope to view the opal is a much harder task.

Seen This Week: Fruits and Seeds

Musings & News, Phenology, Plants & Fungi, Trees
“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)

BONUS! Who eats monkey balls?

video embedded from Ghosts of Evolution on YouTube

Some Plants Are Simply Female

Plants & Fungi, Trees
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.

Compare this “perfect” bisexual flower diagram …

Diagram of a flower with both female and male parts (image from Wikimedia Commons)

… to single sex flowers.

Diagrams of female and male flowers (altered from the perfect flower on Wikimedia Commons)

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!) …

Fruit and fallen leaves from a female gingko tree (photo from Wikimedia Commons)

… and holly trees –> You can’t get holly berries if you have only one tree.

Holly leaves and berries (photo from Wikimedia Commons)

Knowing this, you can sex dioecious plants in the fall. And here we are with spicebush.

Sexing Spicebush

Seen This Week: Sun, Clouds, Acorns

Doves & Chickens, Phenology, Plants & Fungi, Schenley Park, Trees
Red oak acorns rained on us at Biddle’s, 4 Nov 2024 (photo by Kate St. John)

9 November 2024

It’s an abundant year for red oak acorns, also called a “big mast year.” The acorns pictured above rained on us while we sat outdoors at a coffee shop. Their parent tree shades the tables in summer but is not much fun this autumn.

In two days at Schenley Park: Sun through yellow trees on Tuesday. Overcast skies and russet oaks on Wednesday.

Sun through the trees at Schenley Park on Tuesday 5 Nov 2024 (photo by Kate St. John)
Overcast sky, russet oaks and leafless trees at Schenley Park on Wednesday 6 Nov 2024 (photo by Kate St. John)

I took a picture of a bird! An unusual, piebald pigeon.

Piebald pigeon from the side, 5 Nov 2024 (photo by Kate St. John)

The pattern extends to the back of its head.

Piebald pigeon from the back, 5 Nov 2024 (photo by Kate St. John)

In an August article, Grass Carpet in the Woods, I mentioned that “After Japanese stiltgrass goes to seed in early fall it dies and becomes a brown drape over the landscape in winter.” Well, here it is draping part of Frick Park near Wilford’s Pines.

Dead Japanese stiltgrass draping the landscape at Frick Park, 7 Nove 2024 (photo by Kate St. John)