Within its natural range, black walnut grows well only on high- quality sites. Such sites are also attractive for growing row crops. However, there are cases where black walnut is preferable to row-crops because of small field size or difficulties with cultivation. You may be able to plant such parcels to black walnut trees without taking acreage away from current row crop production.
Poor sites have characteristics which will stress black walnut trees. These characteristics include insufficient moisture, too much moisture, harsh conditions from steep slope, hard pans and shallow soils with bedrock or gravel that restrict root growth. Unfortunately, you cannot improve a poor site.
To grow black walnut profitably, plant on suitable soils. Choose well-drained, loamy soils with a pH between 5 and 8. Generally, smooth and gently rolling landscapes offer the best sites.
Study sites carefully for proper soil texture and drainage, since these are often the more limiting factors. In mountainous terrains, middle to lower north- and east-facing slopes as well as stream terraces and floodplains often make adequate walnut sites. Table 1 lists site considerations for black walnut.

Table 1. Site selection for black walnut.