Acorns are all over the trails in fall, a thick carpet on the autumn leaves. And then by spring they’ve vanished. Where have they all disappeared to? Well, most are devoured by the astonishing diversity of wildlife that feeds on acorns. Like all nuts, acorns are remarkably high in fats and protein, vitamins and minerals – a nutritional powerhouse, perfect for helping you make it through cold winter nights. Gray squirrels eat acorns, of course. But that’s just the beginning. Wild turkeys are nuts for acorns. So are deer. So are blue jays, chipmunks, red foxes, opossums, raccoons, pileated woodpeckers, red squirrels, yellow-bellied sapsuckers, acorn moth caterpillars, meadow voles, white-footed mice, flying squirrels, gray foxes, mallard ducks, wood ducks, crow .…
Whew! After that onslaught, it’s a wonder there are any acorns left to turn into trees.
To cope with the hordes of eager mouths waiting to devour their babies, oak trees use a strategy called predator satiation. In some years, they produce so many acorns that there’s a fighting chance that a few out of all those thousands might actually germinate.
“Great oaks from little acorns grow,” is a cliché, of course. (According to the Oxford Dictionary of Quotations, it’s been around since the Fourteenth Century.) But how does the process work, exactly? How does a wee baby acorn turn into a three-hundred-year-old giant stretching a hundred feet into the air, weighing many tons?
The acorn, like any baby, may appear to be peacefully asleep, but inside, it’s churning with life and growth. The acorn bides its time until conditions of temperature and moisture are just right. Even though they look similar, acorns of different species do it differently. White oak acorns will germinate soon after they fall. Red oak acorns need a period of dormancy, a nap in the cold until spring rolls around. But when the right moment arrives, the embryonic root tip thrusts through the acorn’s husk like a chick pecking its way out of an eggshell.
We tend to think of young plants as striving upwards to the sun. But at first, the opposite is true. The young root avoids light. It turns away from the sunshine and tunnels into the soil beneath it like a blind white snake, pushing deeper and deeper. It starts to absorb moisture, and this water powers the next step, the growth of the stem and leaves that seek the light.
Only a few acorns sprout, but most don’t survive for long. They’re munched by caterpillars, browsed by deer, weakened by fungi, stepped on by humans. But a few, a very few, survive their perilous infancy. Slow growers, oaks – they don’t do anything in a hurry. It may take years for the youngster to grow ankle-high, then knee-high, then shoulder-high. And then? The sky’s the limit.
So, the next time you see a humble acorn on the trail, give it some respect. If it survives the deer and the turkeys and the squirrels, the bugs and the lawnmowers and the fungus, it might be the one that turns into a mammoth tree, a magnificent being that will long outlive you. You never know which acorn will be the one to touch the sky.
Anita Sanchez, a longtime friend of the Arboretum and contributor to the Newsletter, is an award-winning author of books on nature for both children and adults. “Hello, Puddle” is her most recent book for young people.
Volume 40 , Number 1