We’re having the kind of year that could put Chicken Little into a sanitarium.
Acorns – thousands of them – raining down on our decks, our lawns, our poor defenseless heads.
They keep us awake at night with their plunk-plunk-plunk. They turn the water in our swimming pools a lovely shade of Earl Grey. And they have us considering buying hard hats.
Is the sudden and unrelenting abundance of acorns a side effect of global warming? Is it a sign of an approaching apocalypse? Does it mean that our oak trees, already under the threat of sudden death, are under a new attack?
Thankfully, none of the above. It’s just nature being nature.
Bethallyn Black, urban horticulturist with the University of California-Davis Cooperative Extension program, says the acorn glut is part of a natural cycle. Once every few years when conditions are right, oak trees produce acorns in abundance. It is a botanical phenomenon known as a “mast.” And is this ever a mast year.
Masts occur in cycles, Black says, coming once every four to 10 years. A number of factors come into play to trigger a mast, including frosts, drought, spring rain and insects.
Black suspects this year’s mast may have been influenced by the January frost that knocked back insect pests that might otherwise have stunted acorn production, and a particularly dry spring, which may have tipped the oak trees into self-preservation mode.
Research done at UC’s Hastings Reserve biological field station in Monterey County indicates that the heavy acorn sets for valley and blue oaks are most dependent on the weather in April, Black says, when pollination occurs. A warm April often means more acorns.
Acorn production for Quercus agrifolia – live oaks – seems to be related to the rainfall that occurred two years prior.
Whatever the reason, Jill Harcke of Pleasant Hill is just happy to be experiencing it. Harcke has been watching her yard fill with acorns for the past two months. She first noticed it when she heard a loud thunk on her deck and then watched a Snickers-sized acorn roll in her opening sliding glass door.
“It was like an E.T. experience,” she says.
Since then, the acorns have been falling fast and furious. And while other people may be complaining about the mess and bother, Harcke says, “I revel in it.”
Harcke is director of the John Muir Mountain Day Camp, a program that aims to enlighten students about the teachings and legacy of John Muir and foster an appreciation for nature and conservation.
“You can’t run a camp and not be delighted by this change in nature,” Harcke says.
Sheri Crane, who lives next door, is not quite as pleased. The oak tree that’s been covering the court with acorns is right in front of her home, and every morning Crane’s husband, Mike, has to sweep off the walk, the driveway and the cars.
Neither Crane nor Harcke can remember a year like this one, although Crane, whose family has lived on the street for 19 years, recalls one almost as heavy back in 1989.
And the reason she remembers it so well is that her then 5-year-old daughter broke her arm when her bike skidded on an acorn. So far this year, Crane says, nothing like that has occurred.
If nothing else, being up to our ankles in acorns should please the wildlife. Acorns are fodder for deer, mice, squirrels, wood rats, jays, quail, band-tailed pigeons, woodpeckers and others creatures that live in or visit our yards. Wildlife enthusiasts recommend gathering the acorns to feed birds, deer and other animals through the winter.
Besides collecting a large supply of food and keeping your lawn and walkways clear, collecting acorns also should prevent mighty oaks from growing in places you don’t want them.
Black says very few acorns that fall actually make it to germination. Researchers say only one in 10,000 will ever produce leaves. But for those that do make it, they can be hard to get rid of. Acorns send down roots very quickly and very deep.
By the time an oak seedling is 6 to 8 inches tall, Black says, it can have a tap root 2 feet long. The deep root improves the seedling’s chance of survival. If the top is eaten by a deer or elk, the root remains to send up another shoot.
Black says she has an oak seedling that grows up from under her deck several times a year. She’s been cutting it back to ground level for 20 years, and it still comes back.
“My recommendation is to dig up seedlings in beds with trenching shovels to get as much of the root system as possible,” Black says. Or just resign yourself to cutting them back several times a year in perpetuity.”
In the meantime, hang on to those hard hats. The mast still has a ways to go.
Contact Joan Morris at (925) 977-8479 or email@example.com.