Meet the Man D.C. Counts on to Spot Spring

By Michael E. Ruane
Washington Post Staff Writer
Thursday, March 6, 2008

The wind off the Potomac River near Washington's Inlet Bridge still carries the damp chill of late winter. The nearby trees are stark and mostly bare, with some of the young beeches holding their dry leaves from the fall.

But close by the river bank, not far from the Jefferson Memorial, a large shrub stands in the shadow of a holly tree, its tiny yellow buds just starting to open like lanterns against the hues of early March.

It is Cornus mas, a Cornelian cherry dogwood, and to National Park Service horticulturalist Rob DeFeo and other keen observers, it is a trusted sentry, a bright, often-unnoticed herald bearing word that spring is nigh.

Here in Washington -- the capital of spring, as one local booster remarked last week -- the advent of the season means the rebirth of the landscape as well as the coming of tourists, the annual Cherry Blossom Festival and the approximately $150 million the festival generates each year.

So spring's harbingers must be closely watched.

Especially by DeFeo, who today is scheduled to stand up amid a crowd of festival organizers and public officials at the Mandarin Oriental Hotel downtown and issue his 17th yearly ballpark prediction of when the famous pale pink and white blooms should peak.

It is a crucial task -- he says he has been off-target only three times in all those years -- and it is one that requires the skilled observation of winter's closing scenes.

Late last week, with the March 29-to-April 13 festival still a month away, DeFeo, 52, braved a cold wind and brisk temperatures to show some of the clues that spring scatters to tell those who look that the season is changing.

For example, although few may have noticed, the elm trees and the red maple trees are starting to flower, DeFeo said. Some maples even have a broad and distinct reddish tint to their crowns, caused by the swaths of their miniature blossoms.

The fuzzy gray buds of the magnolias are still closed but are fat with moisture and are about ready to bloom, especially those of the elegant, twisting star magnolia,.

Daffodils and day lilies are pushing up green shoots, DeFeo pointed out, and, over in Ash Woods, near the Lincoln Memorial, flowering apricots are in bloom.

Thin, delicate-looking trees, they boldly bloom in February, producing minute flowers of pink, red or white that can be damaged by frost. "The flower gets damaged, not the tree," DeFeo said. "The tree's fine."

The flowering apricot often is mistaken for a blooming cherry tree by early blossom hunters, DeFeo said.

And then, across the Tidal Basin from the Cornus mas, there is the mysterious "indicator tree."

The tree, which has perched there for 60 or 70 years, is probably a hybrid cherry tree, different from but related to the 3,800 cherry trees around the basin and Hains Point.

"We know a lot about what it isn't," DeFeo said, but they are not exactly sure what it is.

The indicator tree is so called because it unfailingly and inexplicably blooms seven to 10 days before the other cherry trees. Old-timers told DeFeo about it years ago.

As the festival draws near, it is an important and reliable clue, so important that DeFeo had a cutting of the tree planted outside his third-floor office at the local National Park Service headquarters in West Potomac Park, where he can keep an eye on it. "It's always early," he said.

In the past, when the cherry blossom festival was one week long, the indicator tree could be a great help in predicting the window of peak bloom. The blooming prediction was made about a week before the festival. "It was real easy to make a forecast," DeFeo said. "You go out and look and you see where it is, and you make a forecast."

But since the expansion of the festival to two weeks in 1994, DeFeo's prediction must be made more than three weeks in advance of the bloom, and the indicator is less helpful, he said.

Now he must study many other things. "I know the average [peak] date is April 4," he said, and he asks himself, "Are we having an early spring or a late spring?"

He examines daytime and nighttime temperatures, and the duration of warm or cold spells. And he scrutinizes the elms, and maples, the magnolias, daffodils and flowering apricots.

As for the faithful, sun-colored flowers of Cornus mas, their bloom will be over by the time the cherry blossoms peak, DeFeo said. Their work will be done. Until next spring.

© 2008 The Washington Post Company