Peak Bloom for UW Cherry Blossoms Expected in Late March
Cherry trees on the University of Washington’s Seattle campus are waking up and getting ready to say hello. For the 29 iconic Yoshino cherry trees in the UW Quad, peak bloom will likely begin after March 20, according to UW arborist Sara Shores.
“Historically, peak bloom in the Quad typically begins during the third full week of March and goes into the fourth week of March. That seems to be what this year is going to look like,” said Shores. “Right now, I would guess that the last two weekends of March are ideal viewing conditions.”
This post will be updated with the latest estimates, which could change based on weather conditions.
Cherry tree fans don’t have to wait for peak bloom to visit campus. The entire cherry blossom season is a great time to visit and see the trees in bloom. The UW maintains a visitors’ website dedicated to the school’s cherry blossoms, providing tips for getting to campus and maximizing the tree-viewing experience. The site has updates on the status of the blooms as well as details on transportation, activities and amenities. The Quad cherry blossoms also have their own social media accounts on Instagram and X, formerly Twitter. For cherry tree enthusiasts who can’t make the trip, campus webcams are a good option for virtual viewing
The timing for peak bloom — meaning 70% of buds have emerged — varies each year based on weather conditions that the developing buds are exposed to in January, February and March.
“In order to reach peak bloom, buds need to accumulate a certain number of both cold and warm days, known as ‘growing degree days,’” said Marlee Theil, a UW graduate student in the School of Environmental and Forest Sciences.
As of March 8, just over half of the cherry trees in the quad were at the “peduncle elongation” stage of bud development, during which the stalks supporting the florets grow longer. It is one of the last stages before the florets open and the bloom season begins. The remaining cherry trees in the Quad are also progressing normally, albeit one or two days behind.
Since 2018, a UW research group has been monitoring campus blossoms from January to April to create a model that will use weather data to predict the timing of peak bloom. Theil currently leads the monitoring team of more than 20 undergraduates.
“The data that we gather will not just help us know in future years when to come to campus to enjoy the trees,” said Theil. “This will also be a valuable research tool to understand how these trees respond to changing environmental conditions.”
There are more than 100 cherry trees on campus. The main species is Yoshino, including the trees in the Quad. Other varieties include the Higan, Hisakura, Kwanzan, Mt. Fuji and Shirofugen trees that can be viewed at locations across campus. The Yoshino trees bloom earlier than many of the other species.
“Even as bloom season wanes for the Yoshino trees in early April, other trees on campus will be starting,” said Shores.
How long blossoms will remain on the trees this year depends on the weather. Cooler temperatures, less rain and lighter winds all will help keep blossoms on the trees.
For those who wish to avoid crowds on the Quad, visiting on weekdays and in the early mornings are better options. The UW asks that visitors not climb the trees, move their branches or shake their branches, as this can cause damage.