A tree cannot make timber, firewood, nuts or fruit if it cannot hang onto its leaves. Nor can it build up the carbohydrate reserves that are critical to maximum winter cold hardiness. The primary issue with Black Walnuts is anthracnose. Michigan is not particularly severe for disease pressure compared to the mid-South, but that means that our local landrace of Black Walnuts are likely to be deficient in innate resistance.
Selecting "mother trees" on the basis of leaf health is smart business.
As always, you can click on the pictures to embiggen.
|A Black Walnut completely defoliated by anthracnose by September 24, 2015. This tree is growing on Gunnell Road in Eaton County. After a bit, you can start separating out "families" of trees based on defoliation.|
|A tree growing alongside M-50. This tree bears heavily most years.|
|Leaf health is only so-so.|
It is the inside that counts.
|This is a pretty typical nut for mid-Michigan. It was collected on Vermontville Highway. As you can see, the shell is much thicker than M-50 but the kernel is not trapped.|
|This is a local Shagbark Hickory. You can see all of the sinus features in the kernel. Picking out these kernels is slow and tedious work.|
|Nut from M-50 compared to the Gunnell Road nut.|