If you choose to speak with Stregomir (by the fire) he will inform you that the Great Oak may yield many Magic Acorns some years, while other years it may not yield as many.
He then describes what the acorns are used for, explaining that sometimes they are ground up and used for fertilizer to yield a large harvest. While other times they are mixed in with medicines to cure illnesses.
Associated quest Edit
- The magic acorn grants 2 Ability Points when eaten. Geralt can also give the acorn to the villagers, though this changes nothing story-wise, and you lose 2 potential Ability Points.