The month of March is traditionally the best month for tapping maples to collect sap for maple syrup. The sap runs best with daytime temperatures above freezing and nights below freezing. When the days are too hot the sap becomes bitter. When the nights don’t freeze the sap stops running and the season is over.
This winter we’ve had yo-yo weather in the Northeast and Great Lakes states. You can see it in the forecast highs this week from Tuesday 27 Feb through Sat 2 March. The cold front coming through today will result in two nights below freezing. Then temperatures will rise again into the 60s. You can see the new blob of hot weather approaching from the Great Plains on Saturday 2 March.
Maple sugar farmers have had to adjust by starting the season whenever the sap runs — in Pennsylvania that might mean January — and pausing the season when the temperature goes up too high in hopes it will drop again.
This news article from Minnesota shows what their maple farmers are dealing with.
Yes, it’s still February but this winter has been so warm that it’s already time to look for shrimp in the woods.
Last year Adam Haritan at Learn Your Land taught us about fairy shrimp in vernal pools. If you missed his 7-minute video, view it right now to find out what these tiny creatures look like and where to find them.
Amazingly there are 313 species of fairy shrimp (Ansotraca) around the world. Some live in brine water, some live in freshwater. The Eubranchipus genus which Adam mentioned contains 16 species including this female in Poland. You can see the eggs inside her at the root of her tail.
Are you ready to go look for fairy shrimp? Find an isolated ephemeral pool in the woods and look for tiny movement in the water. Here’s a photo to set your size expectations. There’s one at the tip of the fingernail.
Look for vernal pools in the days ahead. In addition to fairy shrimp you’ll find wood frogs and spring peepers. Don’t delay. The end of March may be too late.
Sunrise in Pittsburgh, 7 Feb 2024 (photo by Kate St. John)
10 February 2024
Beautiful sunrises, calm reflections and high water at Duck Hollow were on tap this week in Pittsburgh.
Wind-less clear skies along the Monongahela River at Duck Hollow, 4 Feb 2024 (photo by Kate St. John)Pastel sunrise on 8 Feb 2024 (photo by Kate St. John)
The week began as Winter but ended even warmer than early Spring. The tulips in my neighborhood are well above ground, fortunately without flower buds. One week from today, on 17 Feb, the weather forecast calls for temperatures as low as 19°F.
These tulips think it’s already spring, Pittsburgh, 7 Feb 2024 (photo by Kate St. John)
The tulips survive in my too-many-deer neighborhood because they’re surrounded by buildings and tall fences with no obvious exit other than a narrow driveway.
I thought that the maze of buildings and driveways would protect these Japanese yews in front of Newell-Simon Hall at Carnegie Mellon, but deer found their way in and munched the bushes down to sticks. There’s a lot more to eat here. The deer will be back.
Deer damaged yews at Newell-Simon Hall, CMU, 7 Feb 2024 (photo by Kate St. John)
Afternoon light in Schenley Park, 3 Jan 2024 (photo by Kate St. John)
6 January 2024
Pittsburgh had a rare moment of sunshine on 3 January. I was happy to be outdoors during the Golden Hour in Schenley Park.
This El Niño winter has been so warm that bulbs sprouted in my neighborhood in December. Here are four of the many I found on New Years Eve. That exposed bulb would never have survived in a normal winter like those we used to have just a decade ago.
Flower shoots emerge on New Year’s Eve, 31 Dec 2023 (photo by Kate St. John)
Pittsburgh’s deer won this round.
At Carnegie Museum in Oakland this week I discovered that deer damage near the rear parking lot was so severe that gardeners removed all the Japanese yews. It took two years and an ever-burgeoning deer population to reach this stage.
All the yews have been removed at Carnegie Museum, Pittsburgh, 3 Jan 2024 (photo by Kate St. John)
Last August there were fewer yews than in 2022 because the damaged ones had been removed. Unfortunately the deer were severely browsing the now exposed healthy yews.
Damaged yews at Carnegie Museum in August 2023 (photo by Kate St. John)
Here’s what they looked like in August 2022. Those in front had been eaten bare and died. The next tier was severely browsed and those in back were still normal because the dead and dying yews protected them.
Deer damage on yews at Carnegie Museum, 16 August 2022 (photo by Kate St. John)
The bank of yews could not survive with so many deer.
Despite the popularity of The Christmas Song, you’ll never find nuts of the American chestnut in the wild. By the time The Christmas Song was written in 1945 mature American chestnuts were nearly gone from North America. Today there are so few surviving mature trees that Wikipedia lists only 25 locations though people are always searching.
American chestnuts (Castanea dentata) used to be more abundant than oaks within their native range.
Then in the late 1800s someone imported Japanese chestnut trees that had chestnut blight. Asian chestnuts are immune, American trees are not. First noticed at the Bronx Zoo in 1904, chestnut blight spread quickly and nothing could stop it. By 1950 mature American chestnut trees were gone throughout their range.
Chestnut blight is caused by a fungus that kills the above-ground portion of the tree by getting under the bark and girdling the trunk.
The stump lives and sends up seedlings though they die as saplings. The process repeats — seedlings, sapling, death. Most stumps are at least a hundred years old.
To find a chestnut in the woods I look for the leaves at knee height. The photo below shows a typical American chestnut stump with seedlings. This one has a dead sapling as well.
For over 70 years arborists have been searching for a cure for chestnut blight and trying to breed immune American chestnuts. They have crossed the American chestnut with Chinese chestnuts, then back-crossed the hybrid to another American chestnut. These efforts, supported by The American Chestnut Foundation among many others, take decades to realize any success.
There are several experimental orchards in Pennsylvania. All are protected from deer.
As potentially successful hybrids become available, they are planted more widely — still in protected areas — to test their immunity and build back the chestnut population.
Perhaps in one to two hundred years the nuts of American chestnuts will be easy to find and we’ll appreciate the first phrase of The Christmas Song again.
Acorns are complicated because oaks are extremely diverse. There are about 500 species in the Quercus genus (oaks) plus about 180 hybrids, all of them native to the Northern Hemisphere and Asia.
The best I can do in the field is divide them into the red oak or white oak group based on buds, bark and leaves. Knowing this, I balk at identifying acorns down to the species level. There is only so much room in my brain and I’m saving it for birds.
So with that in mind here are a few acorns I’ve found in Pittsburgh recently. What exact species are they? The only one I know for sure is the burr oak.
Pin oak acorns found on Devonshire St sidewalk (photo by Kate St. John) — see comments for IDBur oak acorn, Schenley Park, Oct 2022 (photo by Kate St. John)White oak acorn without its cap (photo by Kate St. John)Red oak acorns and a mix of fallen leaves, Sept 2020 (photo by Kate St. John)
If you live in Central America you may find this bird on your front porch.
Happy Friday!
We hiked 12 miles along a muddy trail and then stood for five hours in the rain waiting for this magical bird to appear. I’m just kidding. Someone called my guide and said, “Hey, there is a resplendent quetzal on my front porch. Do you want to come see it!” Seriously. pic.twitter.com/p4U22Yfvhp
Buckeyes have always been one of my favorite objects because their skin is smooth and shiny fresh out of the husk, perfect to carry in my pocket like a worry stone.
In America, the native Aesculus are commonly called “buckeyes,” a name derived from the resemblance of the shiny seed to the eye of a deer [a buck’s eye]. In the Old World, they’re called “horse chestnuts”—a name that arose from the belief that the trees were closely related to edible chestnuts (Castanea species), and because the seeds were fed to horses as a medicinal treatment for chest complaints and worm diseases.
Let’s go backwards in the growing season from nut to husk, flower and leaf by examining buckeyes planted in Schenley Park more than 100 years ago.
The large nut pictured at top left is from a European horse chestnut (Aesculus hippocastanum) native to Albania, Bulgaria, mainland Greece and North Macedonia. Each husk contains one to three nuts. Sometimes they’re flat on one side. My favorites are the round ones.
They’re produced from the white flowers that have pink (already fertilized) highlights. Notice that each leaf has seven fat leaflets. The number and shape of the leaflets indicate this is a horsechestnut.
Horse chestnut flowers and leaves (photo by Kate St. John)
In winter horse chestnuts are easy to identify by their large, sticky end buds.
The yellow buckeye (Aesculus flava) is native to the Appalachians and Ohio Valley and is North America’s tallest buckeye tree at 70 feet. Planted as an ornamental in Schenley Park it can hybridize with its shorter cousin, the Ohio buckeye (Aesculus glabra), making identification difficult for non-botanists like me.
Yellow and Ohio buckeye nuts look a lot like horse chestnuts. Seeing the husk is a big help because yellow buckeye husks are smooth …
p.s. The small buckeye nut in the top photo is from the shrub-sized bottlebrush buckeye (Aesculus parviflora), planted in Schenley Park near Panther Hollow Lake. Click here to learn more.
(*) Which Flowers? I could not tell whether the flower photo was yellow or Ohio buckeye. Mary Ann Pike suggests Ohio buckeye in this comment.
The thick green husks began to turn brown immediately and peel off in quarter-moon sections. This piece of husk sat indoors for more than a month before I took a photo of its interior. The dark brown exterior is visible at the bottom edge.
Section of a shagbark hickory husk, Nov 2023 (photo by Kate St. John)
If a nut lasts through the winter its husk looks quite worn out by March. This one was probably uneaten for a good reason.
Shagbark hickory nut that overwintered, March 2021 (photo by Kate St. John)
Shagbark nutshells are slightly oval with a remnant stem and four ribs. When I cracked open the nut I collected, it was a dud. Maybe an insect got to it. This Wikimedia photo of a sawed nut shows the meat.
Though shagbark hickory nuts taste good and can substitute for pecans, shagbarks are not cultivated because …
They are unsuitable to commercial or orchard production due to the long time it takes for a tree to produce sizable crops and unpredictable output from year to year. Shagbark hickories can grow to enormous sizes but are unreliable bearers.
C. ovata begins producing seeds at about 10 years of age, but large quantities are not produced until 40 years and will continue for at least 100. Nut production is erratic, with good crops every 3 to 5 years, in between which few or none appear and the entire crop may be lost to animal predation.
Interestingly, shagbarks (Carya ovata) and pecans (Carya illinoensis) can hybridize in the wild though the hybrids usually don’t produce nuts.
Shagbark hickories are easy to identify by their shaggy bark. Just look up and you’ll see it peeling from the trunk. Young trees can fool you, though, because they have smooth bark (click here to see young bark).
Shagbark hickory tree, Raccoon Wildflower Reserve, March 2021 (photo by Kate St. John)
Shagbarks are one of the first native trees to leaf out so their sap runs early in the spring. Yellow-bellied sapsuckers (Sphyrapicus varius) take advantage of this and drill the trees as they migrate north. The birds move sideways around the trunk as they drill in a ring around the tree. The trees heal the wounds by producing callus tissue that grows outward, almost like lips. These attract the the sapsuckers who then drill the same rings year after year.
Shagbark hickory with yellow-bellied sapsucker drill-rings, Schenley Park, Oct 2017 (photo by Kate St. John)
