The ancestor of this variety grew from a Franquette walnut planted in 1880 by Mrs. Riley Kirk, one of the original settlers of Brownsville, Oregon. The nuts had a very thin shell and were sweeter (“less bitey,” as the local newspaper reported) than most walnuts, and the tree was tremendously productive. Riley Kirk planted an orchard from seedlings of the original tree. After the Kirks died, Mr. and Mrs. John Gross bought the land and operated a nursery featuring the fast-growing and productive Kirk seedlings. The trees’ attributes brought it to the attention of the United States Department of Agriculture (USDA), and the name “Kirk Walnut” was officially given to the tree. Demand for Kirk walnut trees and nuts led to the development of a local walnut industry. Later, Cecil Howe acquired the land originally belonging to the Kirks, collected scions from one of the Kirk seedling trees that showed strong immunity to blight, and planted a grafted orchard. In 1960, the Kirk-Howe variety was registered with the USDA. This variety is included in the National Germplasm Repository at Davis, California.
The original Kirk walnut tree and many others in the Brownsville area fell in the Columbus Day Storm of October 1962. Commercial walnut growers, who had had difficulty competing with the California walnut industry, replanted their lands to hazelnuts. Since then remaining Kirk and Kirk-Howe trees have been proudly pointed out on walking tours of Brownsville, but as of 2019 there is no commercial production.
The Kirk-Howe walnut tree resembles the Franquette but leafs out earlier in the season and is relatively resistant to blight.The tree is said to be especially large, productive, and long-lived. The shells are said to be so thin that you can crack them in one hand. Although in general walnuts taste better when the tree is old and slightly stressed, the Kirk-Howe walnut is by all reports free of bitterness, no matter the age of the tree.