Gardener's Flower Planting Distance

On a rectangular garden plot, the length is twice the width. If a gardener wants to plant a row of flowers along the width of the garden, how many feet from the east end of the garden plot should the gardener plant the flowers if they decide to plant them starting from the west end at a distance of 4 feet?

If the width of the garden is denoted as $w$, then the length can be represented as $2w$. If the garden plot is 20 feet long, what is the value of $w$?