Green can be troublesome, perhaps more in landscape than anywhere else. One of the most commonly used basic greens, Viridian, is a good example of the problem: like vodka, when taken straight, it’s tasteless and way too strong. Straight from the tube or lightened with white it is nothing short of St. Patrick’s Day gone insane and it can easily overpower weaker pigments.
Of course, you could get rid of Viridian and use more friendly greens. Other greens, like Sap Green or Terra Verte, are quite good in landscapes, even directly from the tube. Both are much closer than Viridian to the actual colors and color values of nature and Sap Green is excellent for glazing. But both Sap Green and Terra Verte have a different kind of problem. Both are notoriously weak colors—close to useless if any degree of opacity is desired or if there is a need to mix them with other pigments.
The other solution to the problem is to take one strong green and learn how to adapt and civilize it and rid of the St. Patrick insanity. Virdian is like vodka—not very good by itself, but a great mixer. From this angle, Viridian Green can be an excellent choice, because there are several very dependable solutions to the Viridian problem: mixed with the right colors it can produce earthy and leafy greens that rival Sap Green and Terra Verte and also have greater opacity. Mixed with other colors it can be used to make deep resonant darks that are often preferable to black.
Burnt Sienna and Cadmium Orange mix well with Viridian to produce more mellow, natural-looking greens that can also be lightened with white to good effect. Mixed in different proportions with Burnt Sienna, Viridian can be used to make a range from a leaf green to an olive. Cadmium Orange is stronger than Burnt Sienna and a little bit can nicely modify the Viridian to a similar but brighter effect. Viridian also mixes well with Burnt or Raw Umber and Alizarin Crimson to produce a deep resonant near-black that works incredibly well for shadows. A mixture of Viridian with Raw Umber or Alizarin can be lightened with white to create greyed-out greens. Burnt Umber mellows the Viridian and produces warmer darks and deep greens than wither Alizarin or Raw Umber. So—whatever your feelings about vodka, try mixing your Viridian.