Philadelphia's cherry blossoms are threatened by climate change

Cherry blossom season is starting sooner than ever this year, but climate change is affecting trees all year long.

Why it matters: Climate change has led to rising temperatures and more precipitation over the past century, both in the Philadelphia region and across the state. These conditions can weaken Philly’s beloved cherry blossoms and make them more susceptible to disease.

Threat level: With the weather becoming more unpredictable, cherry blossom trees are acting differently, including blooming earlier, having extended periods of growth and not entering dormancy properly, Vince Marrocco, director of horticulture at the Morris Arboretum, tells Axios.

Marrocco predicts that extreme and fluctuating temperatures in the spring will shorten the blooming window for cherry blossoms and cause inconsistent blooming periods.

• “The beautiful cherry blossoms that we’ve been used to in the past, where everything’s all in bloom at once, is going to be more and more of the exception than the rule,” he says.

Zoom out: Cherry blossom trees aren’t the only plants affected by our changing climate.

• Warmer weather is making it harder to grow red spruce, atlas cedars and sugar maples, the arboretum has found.
• As a result, Marrocco has introduced more plants from southern climates to the arboretum over the past decade, from live oaks to palms.

What we’re watching: Some cherry blossom trees are already in their first stages of blooming throughout the city, which began about four weeks earlier than expected this year.

• The Shofuso Japanese Cultural Center expects its famed trees to bloom around the week of March 20 — one of the earliest blooms in its history.

Plus: The Shofuso’s annual Cherry Blossom Festival is April 15-16 at the Horticulture Center and Centennial Arboretum in West Fairmount Park