2021 could be a ‘mast year’ for acorns
Are you hearing more taps on your roof than usual? Or maybe a few extra crunches as you pull the car out of your driveway?
Some Americans are seeing more acorns drop than usual this year. If you’re in the same boat, then you could be in the middle of a “mast year” for oak trees, which is when they produce an abundance of nuts.
In Michigan, one resident said the two “epic oaks” outside her house started dropping acorns in bunches this year after not producing any for years. In Connecticut, parts of the state are seeing a sparse output, others see a lot.
If acorn mast years seem a bit random, that’s because they are – in some ways, at least. They can happen on varying scales and don’t occur on a set schedule. They come around as often as once every year or two and can be spurred by winter weather, experts said.
“It has much to do with what’s happening with the weather prior to flowering,” which occurs in the spring for oak trees, said Nina Bassuk, a professor and director of the Urban Horticulture Institute at Cornell University.
A mild winter can often mean more acorns because white and red oak trees are able to produce more of them when they start creating seeds in the spring. But a harsh winter or a springtime freeze can lead to very little acorn production, or sometimes none at all.
This is where climate change potentially plays a role in the frequency of acorn mast years, Bassuk said. Mild winters and no spring freezes mean a better environment for flowering.
In the Northeast, for instance, this past winter and spring were “phenomenal” for flowering, Bassuk said.
“I think that was because we had a pretty mild winter and any flower buds that did form were allowed to flower as opposed to being killed off by late frost or something like that,” Bassuk said.
And it’s not just acorns that fall in bunches once every couple years. Other nuts like walnuts and hickory nuts go through the same process.
On the whole, the bushels of tree nuts falling don’t mean much more than a nuisance for humans.
Jeremiah Sandler, an arborist in Royal Oak, Michigan, said he gets a lot of calls this time of year about the extra tree nuts. Homeowners tell him they have never seen so many acorns and are worried. He calms them by telling them they have nothing to fear. Nature is doing just what it’s supposed to be doing.
“I like mast years,” Sandler said. “It gets more people looking at trees.”
Contributing: Frank Witsil, Detroit Free Press