Acorns are falling. They hit the roof and the siding. They pile up in the yard and on the driveway. When a stiff wind blows, they sound like a burst of hail. On the ground, they slide under the feet, making for a crunchy or even a treacherous passage. When I’m walking under an oak tree, I consider myself lucky if I’m not beaned in the head.

My yard is not alone. All up and down the street and throughout the area, I’m seeing a bumper crop of acorns. Which leads me to believe it’s a mast year in Fairfax County.

Masting is when a plant produces an abundance of fruits, seeds or nuts. Theories abound for why this happens, but animals are the beneficiary. Squirrels, deer, and even blue jays, which I just learned eat them, too.

The marvel of the mast year is how it affects all the trees in an area. “Not one tree in a grove, but the whole grove; not one grove in the forest, but every grove; all across the country and all across the state,” writes Robin Wall Kimmerer in Braiding Sweetgrass. “The trees act not as individuals, but somehow as a collective. … All flourishing is mutual.”