(Mountain Grove) – Our native black walnut, Juglans nigra, is large deciduous tree between 75 to 100 feet tall with an open rounded crown. Its leaves are late to emerge in spring and one of the first to drop in fall. Separate male and female flowers appear in late spring (May-June) both on the same plant. The male flowers are borne on long catkins and the female flowers appear in short terminal spikes. Female flowers give way to edible walnuts, surrounded by a yellow-green husk. Nuts mature in autumn and fall to the ground. After the husks are removed or crumble away, the kernels can be removed from the shell.
Black walnuts are harvested for commercial sale. The wood from this tree is highly valued for making cabinets, furniture, gunstocks and fine veneers. In fact, walnut veneer is so valuable that walnut trees are actually “rustled” just like cattle. Selections of native trees from the wild have been made primarily for improvement of lumber.
John Avery, fruit grower advisor at the Missouri State Fruit Experiment Station is cooperating with Brian Hammons of Hammons Products Company in an evaluation of improved selections of black walnut trees for nutmeat production. Characteristics of trees with improved nutmeat production include lateral bud fruitfulness for increased yield and earlier maturity, late leafing to avoid frost damage, and disease resistance as well as nut quality.
In 1991, Avery established seedling rootstocks from walnuts collected at the station. He then grafted varieties of walnuts onto the established seedlings between 2000 and 2005. Avery explains that, “The nuts are collected, de-husked and shipped to Hammons for crack-out. The percent nut meat is recorded after crack-out. I now have five years of yield data from the trial. ”
Varieties growing at the State Fruit Experiment Station include Emma K, Mystery, Patterson, Hay, DOT, Sparrow, Kwik Krop, Vandersloot, Mintle, Football, Tomboy, Davidson, Ridgeway, and Daniels. “At this point, it looks like Emma K is one of the best with thin shell, high percent nut meat yield, and consistent bearing year after year. I also like Kwik Krop, but it has not proven to be as consistent a cropper in our region,” said Avery, “and the variety Football is quite large as its name implies.” He mentioned that “it takes about 12-15 years to get a yield from trees grafted onto a young rootstock, but it take less time if grafted higher onto an older rootstock.”
Avery is planning a grafting workshop in March of 2013 that will include apples and walnuts. Check our website in the future for more information. Also remember to go to the Hammons Products Home Cooking and Baking Center linked from their homepage at http://www.black-walnuts.com/ for great black walnut recipes. After all, Native Americans not only used black walnuts for food, the Missouri Botanical Garden plant finder mentions that they used the husks to stun fish and make them easier to catch. I can’t think of a better native crop to feature at Thanksgiving in stuffing, vegetable dishes and desserts.
For more information, comments or questions concerning this column, contact Marilyn Odneal at MarilynOdneal@missouristate.edu; or write to Missouri State Fruit Experiment Station, 9740 Red Spring Road, Mountain Grove, Mo. 65711; or call (417) 547-7500. Visit our Web site at http://mtngrv.missouristate.edu.