Category Archives: Trees

Pinyon-Juniper: A Widely Spaced Forest Only 10 Feet Tall

Gunnison River flows through pinyon-juniper forest at Dominiguez-Escalante National Conservation Area (photo from Wikimedia Commons)

Tuesday 22 April 2025: Grouse Lek Extravaganza with She Flew Birding Tours.
Day 4: Colorado National Monument, Coal Canyon, to Craig

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.

Two people walk through a pinyon-juniper woodland at Dominiguez-Escalante NCA (photo from Wikimedia Commons)

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 pine in Utah (photo from Wikimedia Commons)
Pinyon pine foliage, cones and seeds (photo from Wikimedia Commons)

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.

video embedded from KOB 4 TV on YouTube
Utah juniper (Juniperus osteosperma)
Utah junipers in Utah (photo from Wikimedia Commons)
Utah juniper scaled leaves, female and male cones (photo from Wikimedia Commons)

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.

video embedded from Badgerland Birding on YouTube

In addition to a “pinyon” and “juniper” species, the Colorado Birding Trail: Pinyon-Juniper Woodland lists the birds that make the area home for at least part of the year:

Bird species that breed almost exclusively in or near pinyon-juniper in Colorado include Black-chinned Hummingbird, Cassin’s Kingbird, Gray Flycatcher, Gray Vireo, Pinyon Jay, Bewick’s Wren, Juniper Titmouse, Bushtit, Black-throated Gray Warbler, Black-throated Sparrow, and the rare but spectacular Scott’s Oriole. In addition, this habitat may host Common Poorwill, Ash-throated Flycatcher, Plumbeous Vireo, Blue-gray Gnatcatcher, and Woodhouse’s Scrub-Jay. In winter it can be crawling with mixed-species flocks of thrushes, including American Robin, bluebirds, and Townsend’s Solitaire.

Colorado Birding Trail: Pinyon-Juniper Woodland

But we’d have to stay throughout the year to see them all.

Seen This Week: Sunshine and Flowers

Bent and broken tree leans at Raccoon Wildflower Reserve, 13 April 2025 (photo by Kate St. John)

18 April 2025

Several days were sunny this week so I made sure to get outdoors.

At Raccoon Wildflower Reserve on 13 April I encountered a broken tree which I have seen many times before, but this time it had a shadow that nearly touched the far end. The brightly lit forest floor also shows why wildflowers bloom in April. They are flooded with light before the trees leaf out.

Best Photo of the week, though not a native wildflower. Purple deadnettle (Lamium purpureum) is blooming throughout western Pennsylvania.

Purple deadnettle, Frick Park, 14 April 2025 (photo by Kate St. john)

The day warmed up considerably at Raccoon Wildflower Reserve on 13 April. I could almost watch the flowers opening.

Trout lilies (Erythronium americanum) were just beginning to bloom along the south-facing cliff.

Trout lily, Raccoon Wildflower Reserve, 13 April 2025 (photo by Kate St. John)

Spring beauties (Claytonia virginica) were everywhere.

Spring beauties, Raccoon Wildflower Reserve, 13 April 2025 (photo by Kate St. John)

Sessile or toad trillium (Trillium sessile) was still in bud, though even when it blooms it barely opens.

Sessile or toad trillium still in bud, Raccoon Wildflower Reserve, 13 April 2025 (photo by Kate St. John)

Virginia bluebells (Mertensia virginica) were still in bud on Sunday but they’ll be open today.

Virginia bluebells in bud, Raccoon Wildflower Reserve, 13 April 2025 (photo by Kate St. John)

Beavers have been busy along Raccoon Creek. Unfortunately this tree looks doomed.

Evidence of beavers at Raccoon Creek, Raccoon Wildflower Reserve, 13 April 2025 (photo by Kate St. John)

Next week promises to be warm and sometimes sunny. It’s a good time to get outdoors.

Seen Last Week: Flowers and First Leaf Out

Sharp-lobed hepatica, Barking Slopes, 25 March 2025 (photo by Kate St. John) …Those are not its leaves.

29 March 2025

This week saw the real beginning of flower and leaf activity at Schenley Park, Aspinwall Riverfront Park, Barking Slopes and Raccoon Wildflower Reserve.

Flowers and …

Weather makes all the difference for spring wildflowers. They show off on sunny days.

The best weather by far was on 25 March at Barking Slopes where I found a single blooming sharp-lobed hepatica (Hepatica acutiloba), lots of harbinger of spring (Erigenia bulbosa), cutleaf toothwort (Cardamine concatenata) in the bud, and coltsfoot (Tussilago farfara) opening to the sun.

Harbinger of spring, Barking Slopes, 25 March 2025 (photo by Kate St. John)
Cutleaf toothwort flowers in bud, Barking Slopes, 25 March 2025 (photo by Kate St. John)
Coltsfoot, Barking Slopes, 25 March 2025 (photo by Kate St. John)

The ramps (Allium tricoccum) are up.

Ramps! Barking Slopes, 25 March 2025 (photo by Kate St. John)

Yesterday it rained while I visited Raccoon Wildflower Reserve, though it was sunny for half an hour at the start. These spring beauties (Claytonia virginica) were open early on … before I got wet.

Spring beauties, Raccoon Wildflower Reserve, 28 March 2025 (photo by Kate St. John)

Speedwell (Veronica persica) was hiding in the grass at Aspinwall Riverfront Park last Monday. Beautiful color.

Speedwell, Aspinwall Riverfront Park, 24 March 2025 (photo by Kate St. John)
Trees: A Hint of Green and First Leaf Out

Leaf out begins in the City long before the outlying areas. On 27 March at Schenley Park the willows gave a hint of spring and native buckeyes were already leafing out.

Willows greening up at Schenley Park, 27 March 2025 (photo by Kate St. John)

At this time of year a tree that looks red at the top is a probably a flowering red maple (Acer rubrum) — like this one in Schenley Park.

Red maple in flower, Schenley Park, 27 March 2025 (photo by Kate St. John)

I always search for low hanging branches to photograph the flowers. On 19 March this female red maple flower was easy to reach. The male flowers are yellowish because of pollen.

Red maple flowers, The Carnegie, 19 March 2025 (photo by Kate St. John)

Also on 19 March, yellow buckeyes (Aesculus flava) were already leafing out.

Yellow buckeye leafing out, Schenley Park, 19 March 2025 (photo by Kate St. John)

By 27 March the bottlebrush buckeyes (Aesculus parviflora) had sizable leaves.

Bottlebrush buckeye leafing out, Schenley Park, 27 March 2025 (photo by Kate St. John)

For the next three days it will be very cloudy in Pittsburgh but the temperature in the city will range from 59°F to 78°F — basically 60-80°.

I expect more flower and leaf activity before it turns cold on April Fools Day. Cold. No kidding.

From Acorn to Oak Tree: Timelapse in 2 Minutes

screenshot of 84-day old oak seedling from BoxLapse OAK TREE from ACORN timelapse

28 March 2025

Did you know that oaks grow their roots first before they sprout any greenery? This timelapse from Boxlapse shows that it took 60 days of root growth, a full two months, before the acorn sprouted on top.

Watch an oak tree grow from acorn to sapling in 196 days = 6.5 months.

video embedded from BoxLapse on YouTube

Video Description: Some acorns might require cold stratification before they will sprout. The main stem got stuck that’s why it sprouted two new ones instead. And it got a bit stressed by the move from the water to the pot, but it started slowly recovering after a while.

video description from BoxLapse on YouTube

If this acorn had sprouted outdoors it would probably take longer to develop since the water supply, temperature and light levels would vary.

If it had sprouted in the wild in a Pittsburgh park, it would never become a tree because …

This is the biggest threat to oak sapling success in Pittsburgh city parks.
Deer in Frick Park, 17 Aug 2024 (photo by Kate St. John)

Oak seedlings and saplings are a favorite food of white-tailed deer, especially in winter.

In the presence of too many deer, oak saplings are browsed immediately but their root systems are robust so they sprout again and are eaten again, and on and on. The saplings become like bonsai and never grow up. Like this ash sapling in Schenley Park.

A sign of too many deer: Deer-damaged ash sapling, Schenley Park, Oct 2022 (photo by Kate St. John)

The only way to give oaks a chance is to grow them in tree tubes.

Oak growing in a tree tube (Joseph OBrien, USDA Forest Service, Bugwood.org)

That’s why you see tree plantings like this in the City of Pittsburgh.

Oaks planted in tree tubes (Scott Roberts, Mississippi State University, Bugwood.org)

Seen This Week: Sycamore Snow

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)
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.

Wikipedia American sycamore account

You’ll be able to identify American sycamores easily before leaf out. Look for the white upper trunks of large trees along stream and river banks.

Sycamores on the banks of Raccoon Creek, Beaver County, PA, 28 Feb 2018 (photo by Kate St.John)
Sycamores on the banks of Raccoon Creek, Beaver County, PA, 28 Feb 2018 (photo by Kate St.John)

Seen This Week: Winter Weeds and 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

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

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

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?

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)