D.C. cherry blossoms near peak bloom

WASHINGTON – With the recent onset of springlike weather, Washington, D.C.’s famed cherry blossoms buds are inching ever closer to the promised land of peak bloom.

On Monday, they reached “peduncle elongation,” which is the penultimate stage before the Tidal Basin is overwhelmed by both magnificent flowering trees and an onslaught of tourists.

Peak bloom generally occurs about six to 10 days after this stage in which the stalks of the cherry blossoms extend and nascent flowers, though closed, are visible. It follows the “extension of florets” stage, which was reached Friday.

At peduncle elongation, the fourth of six stages in the bloom cycle, blossoms become vulnerable to the elements and temperatures below 28 degrees can cause damage. This happened in 2017, when a cold snap damaged about 50 percent of the flowers.

Before achieving peak bloom, the blossoms still must pass through the “puffy white” stage, the fifth of six in the cycle. At this stage, the flowers begin to open. Usually, this happens about four to six days after peduncle elongation.

Peak bloom, the final stage, is reached when 70 percent of the cherry blossoms flower along the Tidal Basin.

Right now, the forecast for peak bloom (issued in early March) between April 1 and 5, centered on April 3, seems right on target. The National Park Service’s peak bloom forecast between April 3 and 6 also seems on track, although probably closer to the early side of the window.

Peak bloom is thus set to occur right in the middle of the National Cherry Blossom Festival, which runs March 20 to April 14.

Once peak bloom is reached, flowers can remain on the trees for a week or so. But in some years, petals fall off sooner because of wind, rain or frost.

Last year, peak bloom occurred April 5.

Since records began in 1921, the average peak bloom date has advanced about five days earlier in the year as March temperatures have warmed. Although the recent 30-year average date of peak bloom is March 31, the average peak bloom date from 1921 to 1950 was April 4.

The earliest peak bloom on record occurred March 15, 1990, while the latest was April 18, 1958.