Johnson's signature works are usually small in format, tightly painted, delicately handled and richly colored Based on copious preliminary drawings and studies of specific trees in their natural environment, his paintings are accurate and inviting representations of Northeastern scenery and 'exquisite examples of the style that is now called Luminism.'
Johnson's most notable pieces are characterized by their small size, meticulous brushstrokes, delicate execution, and vibrant colors. These works depict accurately and invitingly the natural landscapes of Northeastern America, showcasing a refined style that is now recognized as Luminism.