Juglans major
Arizona Walnut, Arizona Black Walnut
Photo: M. Ritter, W. Mark, J. Reimer courtesy of SelecTree
Juglans major, Arizona walnut, is a medium to large deciduous tree. It has a spreading crown of pinnate foliage and produces edible nuts.
Mildly susceptible to Thousand Cankers disease; likely susceptible to mistletoe; susceptible to aphids, sooty mold. Moderate root damage potential. Allergy health hazard.
Poor potential utility as an urban tree based on evaluation of 11 trees, slightly unhealthy crown, 73% survival, moderate growth rate. Herbivory and leaf discoloration found on a few individuals. Several field trial plants were lost at transplant, roots seem to be sensitive.
We started both fresh seed and 4 month old seed with both receiving a 2 day bleach soak then 120 day cold stratification in moist perlite in plastic bag in refrigerator. Both had equally good germination with the same treatment. Seedlings are fast-growing with a nice form.