He made the two low mounds already mentioned and planted thereon weeping willows.

He set out stocks of imported hawthorns, four yellow jessamines, twenty-five of the Palinurus for hedges, forty-six pistacia nuts and seventy-five pyramidical cypress, which last were brought to him by the botanist Michaux from the King of France.

As 1786 was one of the wettest summers ever known, his plants and trees lived better than they had done the preceding year.
During this period and until the end of his life he was constantly receiving trees and shrubs from various parts of the world.

Thus in 1794 he sent to Alexandria by Thomas Jefferson a bundle of "Poccon [pecan] or Illinois nut," which in some way had come to him at Philadelphia.

He instructed the gardener to set these out at Mount Vernon, also to sow some seeds of the East India hemp that had been left in his care.