Nothing exposes a beginner landscape faster than green straight from the tube. Phthalo green and permanent green exist in almost no natural landscape — real foliage is duller, warmer, and endlessly varied. A single summer tree holds thirty different greens. Here's how to mix them all from a handful of pigments.
Mixing your own green forces variety, and variety is what reads as "natural." The four workhorse combinations: ultramarine + yellow ochre gives soft, grey-leaning sage — most distant foliage is this. Ultramarine + cadmium yellow gives a controllable mid-green for general foliage. Phthalo blue + lemon yellow gives vivid spring green — use sparingly, for sunstruck leaves only. Black + cadmium yellow gives a surprisingly beautiful olive that landscape painters have used for centuries.
Viridian and sap green are useful — as ingredients, never as-is. Viridian + burnt sienna makes a huge range of believable foliage greens. Sap green + alizarin gives deep warm shadow-green. The rule: tube green must always be modified by something warm (red, sienna, ochre) before it touches a landscape.
Flat green kills a landscape even when the colour is right. Every mass of foliage needs at least three greens: a light green for the sunstruck top (lean yellow, even orange), a mid green for the body, and a dark green for the shadow interior (lean blue or violet — shadow foliage is cooler, not just darker). Paint them as distinct shapes rather than blending, and the tree will sit in light.
Atmospheric perspective desaturates and cools everything. The same tree that's rich olive up close is grey-sage at 500 metres and blue-grey at the horizon. If your background trees use the same green as your foreground, the painting will look flat no matter how good the drawing is. Add sky colour (blue + white) to every green as it recedes.
The reason fake greens sneak in: your brain paints the green it expects, not the one in front of you. Squint Lab shows you the truth — load your landscape reference and its colour-mass mode reduces the scene to its actual dominant colours. Most people are shocked how grey and warm their "greens" really are. Tap any area and it suggests the pigment mix from paints you own.
See the real greens in your reference — free