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Walnuts and butternuts of the FWG by Dale Crook
Six species are native to North America, but only two of these, the black walnut (Juglans nigra L) and the butternut (Juglans cinerea L) are found in eastern Canada. The black walnut is one of the most valuable hardwood species native to North America. The butternut is not an important commercial species, and is subject to a major fungal disease commonly called "butternut canker."
Three walnut trees had fruit and each tree had an estimated crop of over 50 nuts. Although most of the nuts have now disappeared (hopefully to squirrels), some remain on one tree overlooking the pond which can be seen from the Bill Holland trail near the baseball field fence. No butternut trees had nuts this year. Although walnuts and butternuts are similar, I found the following characteristics useful in identification:
All of the walnut trees appear healthy but some of the butternut show the telltale signs of the canker fungus. In the early stages of infection, black sooty patches appear on the bark surface. Young cankers exude a black fluid that dries in the summer. The cankers can eventually girdle a tree causing death. On the whole, the butternut canker disease at the FWG appears to be in the early stages. Most trees appear healthy, but the fact that none produced fruit probably indicates they're infected. Diseased trees usually die within several years. There is no known cure for the disease. Hopefully, we might have some trees resistant to the disease. Some other problems were found. Our notorious swallowwort and buckthorn are affecting some trees as well as Virginia creeper. The nut trees with their long compound leaves are particularly vulnerable to the strangling swallowwort. Some trees were being crowded by buckthorn and other trees were covered with Virginia creeper and grape vines. Our plan is to leave any nuts for the squirrels who, besides eating and storing them, will inevitably plant some. We plan to tag the trees in some way and maintain an inventory. By so doing, we can monitor the status of the butternut canker and record the nut crops. Work on buckthorn removal will continue and vines can be cut, but the only recourse for the swallowwort scourge is constant surveillance to cut or dig out the stuff, especially around young trees. Excellent information on all nut trees can be found on the web site of the Eastern Chapter Ontario Society of Nut Growers (ECSONG) at http://www.ecsong.ca
 Text: Dale Crook © Fletcher Wildlife Garden Our e-mail address |
FINDING SOME BLACK WALNUT TREES at the FWG loaded with nuts was exciting and aroused my curiosity about the walnut trees generally.
The FWG contains a total of 48 walnut and 15 butternut trees. The trees range from seedlings under 5' tall to several that are over 20'.