Category Archives: Phenology

Does Spring Still Move 13 Miles A Day?

Climate Change, Phenology, Plants & Fungi
Crocuses blooming in Germany, early March (photo from Wikimedia Commons)

There’s a rule of thumb from the last century that says “Spring moves north 13 miles a day.” On average this means that if crocuses began blooming in Morgantown, West Virginia a week ago they ought to start blooming in Butler, PA today.

However this year’s spring is so early and so hot that I’m wondering if the rule is still true. The animated map below shows spring leaf out moving north from 1 January through 10 March 2020. Some days spring leaps many miles.

Spring Leaf Index as of 10 Mar 2020 (animation from USA National Phenology Network)

According to the USA National Phenology Network, spring is many weeks ahead of schedule, particularly in the eastern US. It’s “three to four weeks earlier than a long-term average (1981-2010) in some locations. Washington, DC and New York City are 24 days early, Nantucket is 30 days early.” Wow!

Leaf out in Pittsburgh began in early February, tulip leaves emerged in late February and I saw the first crocus bloom last week.

So what do you think? Is spring moving faster than it used to? Or just sooner?

Follow the signs of spring at the USA National Phenology Network and Journey North. Here are some cool maps that track what’s going on:

(photo from Wikimedia Commons; map from USA National Phenology Network; click on the captions to see the originals)

Despite The Cold, An Early Spring

Climate Change, Phenology, Plants & Fungi, Weather & Sky
Honeysuckle buds March 2019 vs Feb 2020 (photos by Kate St. John)

Except for a 10 degree cold snap in the last 24 hours, we’re having an early Spring.

So far this year temperatures in Pittsburgh have been 10-34 degrees above normal a third of the time. January 11 was 34 degrees above normal at 71 degrees F.

Honeysuckle bushes responded by leafing out. Last Monday (10 February 2020) I found open honeysuckle buds in my neighborhood. I took a similar photo last year on 11 March 2019 but it was whole month later and the buds were not as open.

According to the USA National Phenology Network, Spring is three weeks ahead of schedule in the southeastern US:

Spring leaf out has arrived in the Southeast, over three weeks earlier than a long-term average (1981-2010) in some locations. Charlottesville, VA is 24 days early, Knoxville, TN is 20 days early, and Nashville, TN is 18 days early.

— Status of Spring USANPN.org

Here’s what it looks like on the map as of 14 February 2020.

Spring Leaf Index as of 14 Feb 2020 (animation from USA National Phenology Network)

Despite the cold, today will warm to almost 40 degrees in Pittsburgh and to 52 by Tuesday. I think we’ll still have an early Spring.

(photos by Kate St. John, map from USANPN.org)

Outdoors in Early January

Phenology, Plants & Fungi
Privet berries, North Park, 1 Jan 2020 (photo by Kate St. John)

Sometimes we think Pittsburgh is boring in January but there’s still a lot to see outdoors. On New Years Day I joined the Botanical Society of Western PA for a walk in North Park. Here’s what we found.

Above, black privet berries (Ligustrum genus) stand out against the sky. Privet, an invasive plant, is found at the old farm along Irwin Road. The house and barn no longer stand but ornamental trees and shrubs remain, including the Ozark witchhazel (Hamamelis vernalis) we always trek to see. Our hike leader, Richard Nugent, said it will bloom pink in February. Here’s a bursting bud.

Ozark witchhazel buds, North Park Irwin Road, 1 Jan 2020 (photo by Kate St. John)

Unusual trees caught our attention, some with burls, others with holes. Two of the best are pictured below.

Large burl at North Park, 1 Jan 2020 (photo by Kate St. John)
A heart-shaped hole, North Park Irwin Road, 1 Jan 2020 (photo by Kate St. John)

We also saw and heard red-tailed hawks circling overhead. (example photo below)

Two red-tailed hawks soaring in winter (photo from Wikimedia Commons)

In January they claim territory with lots of circling and screaming. Here’s what they sound like. No, that is not the sound of an eagle.

During winter expect the unexpected. There’s more to see than you’d think.

(plant photos by Kate St. John, red-tailed hawk photo by Melissa McMasters via Wikimedia Commons; click on the caption to see the original)

Seen This Week In Schenley Park

Phenology, Schenley Park
Witch hazel flowering in Schenley Park, 24 Dec 2019 (photo by Kate St. John)

I found three things in Schenley Park on Christmas Eve:

  • Witch hazel blooming,
  • Gray squirrels searching for nuts,
  • An eastern screech-owl at his roost.

Tiny spider webs span a few petals of the witch hazel flower shown above. These winter flowers are pollinated at night by owlet moths.

Squirrels were busy in Schenley Park this week. Some are so black that they look like a black hole in the landscape. Despite his color he’s just an eastern gray squirrel.

A gray squirrel who’s black in Schenley Park (photo by Kate St. John)

This particular eastern screech-owl has been spending the winter in Schenley Park since at least 2015-2016. I saw him on Christmas Eve but my cellphone photo was too poor to use. Here’s a photo I took in January 2017.

Eastern screech-owl, Schenley Park (photo by Kate St. John)
Eastern screech-owl, Schenley Park, 2017 (photo by Kate St. John)

Don’t forget to spend time outdoors in late December. There are still cool things to see.

(photos by Kate St. John)

October Plants

Phenology, Plants & Fungi
Japanese barberry, Moraine State Park, 13 Oct 2019 (photo by Kate St. John)

October weather is here and the trees are starting to change color in southwestern Pennsylvania. On the ground I found additional evidence of autumn last weekend.

Above, the shiny red fruits of Japanese barberry (Berberis thunbergii) hang from thorny branches. Watch out if you approach them, not because of the thorns but because of ticks. This invasive shrub creates thickets with the perfect micro-climate for black-legged ticks and their favorite host, white-footed mice.

Burdock, nature’s velcro, is still in bloom. The tiny hooks coating the sepal will soon dry out and cling to your clothes as you pass by.

Burdock still blooming, Moraine State Park, 13 October 2019 (photo by Kate St. John)

Though burdock (Arctium minus) is an alien invasive, a local insect has found it tasty. Notice the trail of the leaf miner, highlighted below.

Burdock with leaf miner activity, 13 Oct 2019 (photo by Kate St. John)

Meanwhile a native plant called Lycopodium or groundpine is in autumn dispersal mode. It has sent up tall pale green structures called strobili that will release the plant’s spores(*).

Lycopodium, Moraine State Park, 13 Oct 2019 (photo by Kate St. John)

Lycopodium is a very ancient plant. It’s the last living relative of Lepidodendron, a mighty tree that predates the dinosaurs.

(photos by Kate St. John)

(*) Spores definition from Google dictionary: Spores are minute, typically one-celled, reproductive unit capable of giving rise to a new individual without sexual fusion, characteristic of lower plants, fungi, and protozoans.

Confusing Fall Asters

Phenology, Plants & Fungi
Asters, Raccoon Creek State Park, Lake Trail, 27 Sep 2019 (photo by Kate St. John)

It’s late September and asters are blooming throughout western Pennsylvania. I found several patches of purple asters yesterday on the Lake Trail at Raccoon Creek State Park.

These two may be the same species. They have similar leaves and their colors matched in real life though the camera shows them differently. It’s a trick of the light. Cameras are notorious for distorting purple / blue.

Asters, Raccoon Creek State Park, Lake Trail, 27 Sep 2019, 12.18p

I haven’t identified these flowers. My Newcomb’s Wildflower Guide has 10 densely packed pages of asters and that’s not all possible species.

Do you think fall warblers are confusing? Asters (and goldenrods) are the last frontier!

(photos by Kate St. John)

Tiny Hemlock Pest Has Hatched

Insects, Phenology, Trees
Hemlock woolly adelgid nymphs (photo by Elizabeth Benton, University of Georgia, Bugwood.org)

A week ago I received a message from the USA National Phenology Network that hemlock woolly adelgids would hatch very soon in Pittsburgh and the southern Appalachians. This is worrisome because the nymphs are the active phase of this forest pest.

Hemlock woolly adelgid hatch announcement from USA NPN

Originally from Japan, hemlock woolly adelgids (Adelges tsugae) kill eastern hemlocks in 4-20 years by locking on where the needle meets the stem and sucking the lifeblood out of the tree (closeup at top).

The adults are sedentary, attached to a tree. The nymphs, however, are tiny and mobile. They blow on the wind and hitchhike on clothes, equipment, birds and animals. They spread very easily just after they’ve hatched.

The message above says “You should see active nymphs” but you won’t. At 1/100th of an inch they’re smaller than a grain of sand, almost microscopic. And yet, their effect is devastating.

Hemlock woolly adelgids have already killed up to 80% of the hemlocks on parts of the Blue Ridge Parkway and in Shenandoah National Park. They are eating their way through the Great Smoky Mountains, shown below, and they’re killing hemlocks in Pennsylvania.

Tree death from Hemlock woolly adelgid in the Great Smoky Mountains (photo by Ignazio Graziosi, University of Kentucky, Bugwood.org)

We won’t know how far they’ve spread this spring until they reveal their presence next fall when the females deposit woolly egg sacs on the undersides of hemlock branches.

Hemlock woolly adelgid eggs covered in white “wool” (photo by Steven Katovich, USDA Forest Service, Bugwood.org)

Right now the nymphs are spreading.

Read more about hemlock woolly adelgids at the USA National Phenology Network.

(photos from Bugwood’s invasive.org, message and map from USANPN. Click on the captions to see the originals)

Now Blooming

Phenology, Plants & Fungi, Schenley Park
Bluets at Raccoon Creek Wildflower Reserve, 16 April 2019 (photo by Kate St. John)

20 April 2019

Wildflowers are blooming, elms are setting seed, and some early trees are leafing out. Here’s a sampling of buds and blooms this week in southwestern Pennsylvania.

At Raccoon Wildflower Reserve on Tuesday our group found many flowers opening including bluets (above) and early saxifrage (below). Our complete list is at the end.

Early saxifrage at Raccoon Creek Wildflower Reserve, 16 April 2019 (photo by Kate St. John)

The trail at Racoon Wildflower Reserve was littered with the tips of sugar maple branches, chiseled off by squirrels. These Acer saccharum buds are opening to reveal new flowers.

Sugar maple bud opening at Raccoon Creek Wildflower Reserve, 16 April 2019 (photo by Kate St. John)

Meanwhile in the City where it’s warmer …

This spruce in Shadyside was flowering, too. The pink buds will become cones.

American elms (Ulmus americana) have already set seed. You can tell this is an American (not slippery) elm because the samaras are deeply notched.

American elm samaras from Schenley Park, 16 April 2019 (photo by Kate St. John)

In Schenley Park, invasive Norway maples (Acer platanoides) are leafing out.

Norway maple leaf-out in Schenley Park, 17 April 2019 (photo by Kate St. John)

Spend time outdoors this weekend and see what’s blooming near you.

Here’s are list of flowers seen at Raccoon Wildflower Reserve on Tuesday 16 April 2019, in no particular order. Many flowers were only beginning to open. By now they’ll be in full bloom.

(photos by Kate St. John)

Late April: What’s Next?

Migration, Phenology
Great horned owl with yawning nestling, April 2019 (photo by Dana Nesiti)

Spring is popping in southwestern Pennsylvania. Here’s what to look for in late April.

  • Branching! Great horned owlets are growing up fast. At the earliest nests owlets will walk on nearby branches before the leaves come out. Dana Nesiti photographed this yawning owlet in early April.
  • Nest building: Songbirds are building nests especially American robins, song sparrows and Carolina wrens. House sparrows flutter by with cellophane for their nests.
  • Migration: Blackbirds and tree swallows are here. Gray catbirds are coming soon. Also Louisiana waterthrush, yellow-throated warbler, hermit thrush, ruby-crowned kinglet, blue-headed vireo, brown thrasher, blue-gray gnatcatcher, pine warbler, northern parula, chimney swift, barn swallow and house wren. See them on an outing with the Three Rivers Birding Club.
  • Trees: Flowering trees include redbud, downy serviceberry, cherry and more. “Leaf out” comes in early May.
  • Wildflowers: Violets, large-flowered trillium, trout lilies, Virginia bluebells and much more. Get outdoors with the Botanical Society of Western PA or Wissahickon Nature Club. Visit Enlow Fork on the last Sunday in April for the Enlow Fork Extravaganza starting at 8:00am.
  • Butterflies: Spring azures, cabbage whites, eastern commas, orange sulphurs, red admirals.
  • Turkey season: Be careful if you hear a turkey calling; it might be a hunter. Spring Gobbler hunting season runs from the last Saturday in April through all of May. Junior hunters get a one-day early start on the next-to-last Saturday (April 20).

In late April, spring is happening fast. Don’t miss it!

(photo by Dana Nesiti)

Red Maples Are Complicated

Phenology, Schenley Park, Trees
Male red maple flowers fallen from the tree, 10 April 2019 (photo by Kate St. John)

This week the hillsides turned faintly red as red maples (Acer rubrum) bloomed across southwestern Pennsylvania. The city’s maples bloom sooner than the suburbs so I’ve had a preview of what’s to come.

In Schenley Park the ground under some red maples is carpeted with fallen flowers (above) while others retain flowers that are setting seed (below).

Female red maple flowers on the tree, developing samaras, 10 April 2019 (photo by Kate St. John)

That’s because red maples are sexually complicated. They are polygamodioecious which means some trees have only male flowers, some have only female, and some have both (i.e. hermaphroditic). And they can even switch back and forth:

Under the proper conditions, the tree can sometimes switch from male to female, male to hermaphroditic, and hermaphroditic to female.

Wikipedia Acer Rubrum

Watch your local red maples to see what they’re up to. The one in my backyard dropped its flowers a few days ago. This year it’s a male. 😉

p.s. For more on maple phenology, read Chuck Tague’s blog post: Maples In Spring: A Study in Diversity.

(photos by Kate St. John)