Mount Vernon gardener Joel King examines a tulip poplar that he grew from seed from George Washington's tree. (Adrian Higgins/The Washington Post)

George Washington was supposed to have cut down a cherry tree — that was fake news, folks, because it is well documented that our first president loved trees. In the late 18th century at his Mount Vernon plantation, Washington supervised the planting of hundreds of trees — trees for shade, for beauty, for fruit and for timber. On his travels, he brought trees back to plant at Mount Vernon.

When Washington remade his garden and grounds after the Revolutionary War, he took a special interest in developing the bowling green, the expansive, bell-shaped lawn to the west of the mansion, bounded by serpentine paths that he proceeded to line with trees and shrubs. The paths were made of gravel hauled by slaves from the banks of the Potomac River.

Today, only four trees survive from Washington’s time — he died at Mount Vernon in 1799. Scattered around the bowling green are two tulip poplars and a hemlock, native plants that grow wild in Virginia. The fourth is a white mulberry, the Chinese tree essential to the silk worm industry.

How much longer these trees will live is anybody’s guess. The mulberry, planted on the outside of the Upper Garden, is a sorry-looking specimen. It has two trunks, but they have been beaten back and split, perhaps by lightning.

The trees were dated in 2005, using small core borings that allowed experts to count the rings. A fifth tree from Washington’s time, a swamp chestnut oak, fell in 2014. (In non-public wooded areas outside the garden and grounds, another 10 trees were found to be from the 17th and 18th centuries).

The white mulberry that is one of four surviving trees at Mount Vernon that George Washington would have known. (Adrian Higgins/The Washington Post )

No one is more aware of the mortality of the witness trees near the mansion than Joel King, a Mount Vernon gardener who is on a mission to propagate them. This has been challenging to say the least, because in great age, a tree is less likely to produce viable seed or readily root from a cutting.

His most evident success is a seed-grown tulip poplar that is now three years old, six feet tall and ready for planting in the estate. It resides until the spring in an unheated, plastic covered greenhouse in the private corner of Mount Vernon where a team of gardeners work in several such enclosures and offices. Younger seedlings are now sticks about 12 inches high, and they will remain in the greenhouse to get bigger.

The trees that are surplus to Mount Vernon’s planting needs are joined by other plants sold at an annual plant sale in April.

Cuttings of the tulip poplars have not succeeded, King said, so he is raising the offspring from seed. (A cutting is a clone of the parent; a seedling is genetically more diverse and may be the offspring of two trees). He collects thousands of fallen seeds in November, before the leaf-clearing crews blow them away. He puts them in plastic bags and places them in a cooler to replicate winter conditions. They need this chilling before they will sprout, but even then the germination rate is remarkably low.

Last year, for example, he got only 50 to germinate and survive from the 3,000 or so he collects each autumn.

The mulberry, by contrast, is propagated by cuttings, although that is a challenge, as well. This time last year, King had a dozen that were looking good but crowded. He transplanted them to larger pots, which may have weakened them in advance of an unexpected late April freeze. “It did them in,” he said. He is working on a new batch.

Tulip poplar seedlings growing in the protected environment of a greenhouse at Mount Vernon. (Adrian Higgins/The Washington Post)

The hemlock has proven the trickiest of them all. He has tried cuttings, but they are shy to root. Seedlings will grow, “but I haven’t been able to get them to survive past a year or so. I’m going to try again this year.”

Working here part time for more than four years, this is a dream retirement job for King, who is 61 and captivated by both history and horticulture.

Asked if he feels a lot of pressure to keep these four last trees going, he laughed. “Not pressure, it’s an honor, so I baby every one of them.”

As for George Washington, “people think of him as the president and a general, but he always considered himself a farmer first,” said King. “He and the other Founding Fathers had agricultural backgrounds, and they traded seeds among themselves. That was an eye-opener for me.”

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