Weeping willows (Salix babylonica) are popular landscape trees that were brought here from Asia. They’re easy to notice at this time of year because their drooping stems turn yellow in very early spring. From a distance you see a splash of yellow.
Imported species, especially those from Europe, grew up in a steady climate with few spring surprises so they’re quick to bloom in the spring and late to drop their leaves in autumn.
Meanwhile our native trees are still brown, conservative about producing tender shoots because they know that volatile spring weather can bring a killing frost in April.
Are you tired of winter? Watch for the weeping willow’s hint of spring.
Every year I record the date when most of the trees are bare on my favorite hillside in Schenley Park — the hill at the end of the Greenfield Bridge.
In 2008 the leaves were gone by 2 November. In 2012 Hurricane Sandy stripped them from the trees by 4 November.
Last year the changes happened much later. In 2017, the leaves were still green in late October and more than half were still on the trees on 27 November. Here’s a 2017 slideshow of autumn trees on that hillside.
26 October 2017: Lots of green at the end of October 2017.
4 Nov 2017: More than half of the trees have changed color -- mostly yellow.
12 Nov 2017: About 1/4 of the trees are bare. Some are still green, others are russet.
19 Nov 2017: Lots of ball-tree shapes on the hillside. About 1/4 of the trees are bare
27 Nov 2017: About half the trees are bare. Oak leaves are still hanging on.
This year is similar to last so I wonder … When will most of the trees be bare? November 15? 20? 30? Later?
Let me know how the trees look where you live and vote for the date “When Most of the Trees Will Be Bare” by leaving a comment below.
HINT! Two factors that affect leaf loss on this hillside: (1) More than half of the trees are oaks; oaks drop their leaves later than maples. (2) This city location is warmer than surrounding counties.
Birds that eat insects leave Pennsylvania for the winter but the omnivores, like this house sparrow, stay behind. Food won’t be a problem but it’s going to get cold so the house sparrows get ready in advance.
A study by Lowther and Cink in 1992 found that house sparrows (Passer domesticus) prepare for winter by molting into heavier plumage. Plumage weight increased 70% between August and September alone. Summer weight is 0.9 grams; winter weight is 1.5 grams.
In September the house sparrows put on their winter coats.
(photo from Wikimedia Commons; click on the caption to see the original. This article was inspired by page 153 of Ornithology by Frank B. Gill, 3rd edition.) )
Twenty years ago our fall foliage reached its peak around October 15 but today — only one day before the 15th — the leaves have just begun to change. We had the same situation last year as shown in my photo taken at Moraine State Park on 15 October 2017.
Delayed timing makes it hard to know when fall color will reach its peak but the Pennsylvania Bureau of Forestry (DCNR) is here to help. Check out their Fall Foliage Guide complete with an interactive map and weekly reports. The October 11-17, 2018 forecast map is shown below (yellow means “approaching best color”). Click here or on the caption to see the full report.
Don’t worry if you haven’t gone “leaf peeping” yet in western Pennsylvania. You still have time to see fall colors this month.
It’s early October and the woolly bear caterpillars are back, right on time. But one thing is very odd. The weather is quite hot.
The temperature outlook map shows what we already know: There’s a 70% chance October 2018 will be warmer than normal in Pittsburgh. Highs will be in the 80s today through Wednesday (Oct 7-10)
How is this affecting the plants and animals we usually see in October?
In a normal October 20 years ago, fall foliage color would peak in Pittsburgh by the middle of October, sparrows and ducks would migrate through our area, and the average first frost would occur around October 15. Will those things happen on time this year?
ISeeChange.org is interested in the answer. They’re wondering: “What do you usually expect at this time of year? What does it look like outdoors, sound like, smell like, feel like? Are your expectations met, or are things different? Are there trends in your community that we need to be paying attention to?”
Yellow flowers are abundant in the summer while some of the rarest flowers are purple. Here are four rare plants I’ve never seen.
Dianne Machesney visited Lynx Prairie in Adams County, Ohio in late July to see scaly blazing star (Liatris squarrosa), above. It doesn’t occur in Pennsylvania though we have it’s cousin dense blazing star (Liatris spicata) at Jennings Prairie. The two plants differ in this way: “Scaly” flowers are clustered at the tip, “dense” flowers coat the long spike.