Variegation occurs when some part of the leaf loses the ability to produce enough chlorophyll to maintain the solid green color. When this happens, either a yellowish or whitish color of the underlying cells shows through giving the leaf the variegated appearance that is so distinctive on many cultivars.

In hostas, it has been determined that there are three layers of cells in the leaf tissue which seem to control the colors in the leaf. There are many other cell layers present but these three seem to be unique and the loss of chlorophyll may occur in one, two or all three of these layers. Depending on which layer is affected, the leaf will show one of the characteristic patterns we associate with variegation in hostas.

Layer 1 (L1) - one cell thick at the epidermis of the plant and is especially important in the formation of color pigment at the leaf margins i.e. at the edges.

Layer 2 (L2) - located beneath L1 but does not extend all the way out to the edge of the leaf. This layer has more to do with the color in the center of the leaf.

Layer 3 (L3) - beneath L2 in the leaf and also the only layer that extends down into the roots.