This morning I pulled close to fifteen gallons of sprouted acorns from a friend's yard. Yes, she's sure she doesn't want an oak grove instead of a garden bed (when I saw how thickly the sprouts were filling the space, I asked her to be certain)! The sprouts become woody in stem and root quickly, so I always try to get them as soon as I spot them, while they still make a satisfying "POP" sensation coming out of the ground. The best part about pulling up acorns at this stage is that it's one weed I know for sure will not regrow from any root segments or scattered seeds left behind in the soil.
So I was compelled to absentmindedly yank on a few sprouts in the bed, but before I knew it, I had more than a handful of the weeds. When I looked up, I saw one, two, five. . . nine more sprouts within arm's reach! By the time my friend came out of the house, I had already pulled a large stash of acorn sprouts. My friend was suitably impressed, but why have so many baby oak trees come up in her garden?
Last fall was a mast year for the oaks in this region. This means that the population of oaks in our climate produce near one hundred times more acorns (maple and pine produce an excess of seeds during a mast year) than they usually do. They store surplus energy for years until they are ready to spend it on masting. It's a cunning tactic, one that out-smarts even the squirrels. Increased acorn production allows a large portion of the nuts to go uneaten, and to sprout in the spring. And increased sprouts means more go unseen by gardeners before becoming strong and woody. Another result of the mast, though of little comfort to gardeners, is that the squirrel population is not foiled for long- as it may also grow in response.