People with oak trees on their property may have noticed that its not only raining the wet stuff this year – It's raining acorns. Michael Ellis explains.
In 17th century England a bumper was a large wine glass filled to the brim. “Aye, I’ll have another round of bumpers for me buddies.” Eventually it came to mean a lot of anything, unusually large, but not just wine. Now we use it mostly when referencing a “bumper crop.” And this year many have noticed a bumper crop of acorns.
Beginning a month ago it was literally raining acorns in my backyard from two magnificent oak trees. Both the deciduous valley oak and the evergreen coast live oak dropped thousands, yes thousands, of nuts. It was hard to walk on my deck!
Friends all over the Bay area reported the same spectacle - a biblical flood of copious acorns.
The official term for this periodic explosion of seeds is ‘masting’. Many species of trees and shrubs do this, not just oaks. But since oaks dominate in many California habitats we really notice their effect. Scientists aren’t clear what causes masting but it is surely related to ideal environmental conditions during the spring when the trees are in flower and setting fruit. One statewide study found oak groves from different species 180 miles apart synchronizes their masting! How does that happen?