Ryan Avent defines "green shoots":
For some people, only a return to previous output levels will count as green shoots. For others, only an end to actual contraction where the rate of decline hits zero is a marker of the greening of various shoots. Still others might herald the inflection point at which contraction slows as green, a harbinger of better times to come. When I speak about green shoots in the economy, I’m using this last interpretation. This is quickly dismissed by pessimists who say things like, “Things are just getting worse more slowly!” Quite so. That is exactly how one moves from things getting worse more quickly to things getting better.