West+East Index Description from Planting Instructions Index of Pacific West Botanicals

West/East ( of the Sierras ) : Wet / Dry:

    Within our range of 19 degrees - 49 degrees N. latitude, and east to the
continental divide, an important division in botanical eco-systems is the
Sierras. Wet mild, moist air, flows east from the pacific, dropping
moisture and temperature as it moves eastward over the Sierras.
    Resulting in botanicals which have adapted to both these conditions
growing in the same latitude.
    Western side (wet) is predominantly botanicals that have few or no
special abilities to combat long hot dry periods. These botanicals are
dependent on a seasonal supply, though sometimes slight, of water and
have low tolerance for extreme cold periods. Soils are generally deeper,
and more fertile with longer growing seasons than eastern areas.
     Eastern side (dry) is composed of botanicals which are either fast
growing summer annuals or extremely hardy biennials or perennials and
adapted to minimum moisture requirements ( 20 inches or less ) or are
desert/high desert botanicals which have some unique method to
combat the extreme heat, and low moisture conditions of our
eastern/south and eastern range. Soils in this range are extremely
variable, from small deposits of glacial loess in the north, to alkaline
dry lake deposits over wide areas of our south eastern range. Most,
characterized by thin soils with low humus and moisture content.