John Constable, one of England’s and the world’s most revered landscape painters, spent his career making drawings and painted studies from which he then worked up his famous “six footers”. Constable’s work was enormously influential in France with the Barbizon school of landscape painters, and eventually the Impressionists.
Here is a typical drawing of his and it is instructive for us when learning to see and paint masses of foliage. As you will note, Constable has carefully delineated the values within the foliage masses and used lights, midtones and darks to create form. These areas are not randomly created- they are based on the architecture of the tree. But, you will often have to “mass” these areas of value to create a solid look to your tree. In most cases, there will be many more value changes than you will want to describe. To do so will break up the volume of the form too much.
So, squint down and look for the large value areas. To help you accomplish this, do a little sketch to map out those areas before you start your drawing or painting. This will help you see them as well as design them in a pleasing way. Here is an example of a value map. This kind of sketch can really help organize your values before you start.
Here is another slightly more finished “value map”. As you can see, I have massed the lights and darks and also used mid tones to describe the planes of the foliage. When you look at foliage try to see those planes- where the light strikes the mass, where it turns away from the light, and where it is in shadow. If you squint you can see this clearly. Then the challenge is to “mass” those areas.
Go outside and do a lot of observing of foliage until you begin to see the patterns. Do some simple value maps to gain experience with the idea of massing. Notice the direction of the light and how that affects the values you see. Here are two more simple “value map” drawings, the first showing top lighting and the second depicting lighting from the left top side of the tree. In both simplified drawings, I have identified the lights, mid tones and shadow areas by squinting down and also by simplifying those areas. In Nature, those values will not always be clearly organized. If you try to copy them as you see them, the result will look spotty and break up the solidity of your form. So learning to squint and simplify is the key to success.