No colour has given me as much trouble over the years as green. It seems to be an arch nemesis. That being said, I know that at least some other painters struggle with this particular hue as well. The question is, beyond my own limitations, why? Basic green, if such a colour exists, is pretty much dead center in terms of value. Note the position in the colour wheel, in relation to the black & white scale. In other words, there are as many bright/light greens as there are dark greens. Compare this to yellow, where you can only add so much white before it loses its identity (yellow is the closest to white in the first place). In theory, green should be the easiest colour to use.
The only time I seem to be able to control green is when I tone it down to near earth tones, as in this older landscape, oil on canvas, 16 by 20". An obvious explanation is that green simply isn't for me, and I'm not meant to ever use it. However, what if green's center position on the colour wheel also leads to its difficult application. Since green is middle toned right off the bat, it perhaps lacks an initial punch. Yellow is bright and charged; it needs to be handled carefully. Blue is dark and cold; it needs to be adjusted to surrounding colours. Green is less dramatic; it's just green.