Homer painted Apple Picking in the summer of 1878 during a visit to Houghton Farm, near Mountainville, New York, the country home of his patron Lawson Valentine. Over the course of his four-month stay there, he produced numerous drawings and some 30 watercolors of wholesome farm children in the well-tended orchards and meadows of the Valentine property. Focusing on the effects of sunlight, Homer experimented with ideas from M. E. Chevreul's treatise The Laws of Contrast of Colour (trans. 1859). Specifically, he followed the principles outlined in the section “Modifications Produced by Yellow Light,” which included “Yellow rays falling on Light Blue make it appear Yellow-green” and “Yellow rays falling on Dark Blue make it appear Green-slate,” best seen in the sunlit skirts of the two young apple pickers in this watercolor.

Throughout the composition Homer added paint in discrete strokes working from darkest to lightest without blending. In the apple trees, dabs of light green and yellow mixed with white were applied over a dark green wash to create foliage; transparent yellow was layered over pure white to indicate sunlight on leaves; touches of opaque vermillion represent apples; and strokes of dry black wash form the branches.

The beige wove paper in Apple Picking has darkened somewhat with time, rendering the transparent passages in the background, faces, and skirts darker than Homer had intended, subtly exaggerating the color contrasts.