Additional acreage would be needed to satisfy the demand for processed products, increased domestic consumption, and possibly exports. English Walnuts Juglans regia includes the English, Persian, and Carpathian walnuts. Many think that English walnuts grow only in California. In fact, hardy strains have been growing in the Midwest for three-quarters of a century. While many of the selections of English walnuts grown in the Midwest are fully winterhardy, their resistance to spring frosts presents the most serious challenge for commercial production.
Most walnuts break dormancy during a period when the probability of frosts is great.
New growth that carries the pistillate blooms can be killed by below freezing temperatures. Therefore, the most frost-free sites are necessary for assured annual production. Besides the good air drainage, walnuts require a good loam or clay-loam soil. The soil pH should be neutral to slightly alkaline for best growth. Sandy loam is acceptable providing the sub-soil has a reasonable water holding capacity.