What's actually happening
Jupiter completes a full circuit of the zodiac in about 12 years, spending roughly 12 months in each sign. Virgo is a mutable earth sign ruled by Mercury.
What the tradition makes of it
Jupiter in Virgo is the planet of abundance in the sign of discernment and service. The classical tension between these two — Jupiter's tendency toward excess and Virgo's tendency toward economy — produces a form of growth that is less spectacular than most but more durable. What expands here is competence, usefulness, and the quality of what is done rather than the quantity.
The tradition associates this transit with improvements in health, with advances in practical craft and technique, and with the satisfaction of solving real problems well. The joy of Jupiter in Virgo is the joy of getting things right.
The shadow is the multiplication of tasks and standards without the multiplication of satisfaction. Virgo can always find more to improve; Jupiter can always produce more opportunity to do so. Without a sense of when enough is enough, this combination generates exhaustion under the appearance of productivity.
How to actually use it
Improve the craft. This is good weather for the refinement of existing work — for the second pass, the upgraded process, the careful attention to what has been adequate but not excellent. Let usefulness be the measure of growth.
Attend to health as a form of investment rather than a response to crisis.
When in doubt
What would work better — and is the improvement worth the time it will take?