Shagbark Hickories and Black Walnuts

     Shagbark hickory trees and black walnut trees are a major part of fall in southeastern Pennsylvania farmland, but are not noticed by many people.  These trees traditionally inhabit bottomland woods, which have moist soil.  But both species, being adaptable, have been planted along rural roads and on lawns.  Black walnuts are particularly common on those human-made habitats because many people like to gather the nuts to put in cakes, ice cream and ice cream toppings.
     These hickory and walnut trees have much in common.  In summer the six-inch larvae of regal moths, called hickory horned devils, eat the foliage of both species.  Both kinds of trees are most evident in October, for different reasons.  Both have compound leaves, each leaf bearing several leaflets.  Both types produce nuts that have hard, green husks, that become dark.  Both have hard shells under those husks.  And many nuts of hickories and black walnuts litter the ground and country roads during September and October.
     However, hickories and walnuts have differences, too.  Local shagbarks mostly inhabit stream edges in farmland.  They have striking yellow-bronze foliage in October.  And the one and a half inch, green husks on their nuts have four sections that separate when those nuts fall to the ground.  The inner shell of each nut is off-white and smooth. 
     Black walnuts are abundant in local farmland, particularly along country roads.  Many of them were planted by people and squirrels, which promotes their abundance.  In October, black walnut trees are characterized by having few leaves on their twigs, but having many green, two-inch nuts still hanging decoratively on those twigs, as well as many nuts on the ground and roads under the trees.  The shells of their nuts are dark and grooved.
     Poison ivy and Virginia creeper vines crawl up shag barks and black walnuts, and other structures, to reach sunlight.  Poison ivy vines have red, orange and yellow foliage in September and October, while the leaves of the creepers are bright red at that same time.  Shag bark and walnut trees along country roads are particularly beautiful and enchanting to us because of the striking autumn foliage of those two types of vines hanging from their stout limbs and trunks.  
     Gray squirrels and other kinds of rodents are the only creatures in southeastern Pennsylvania that have jaws strong enough and teeth sharp enough to chisel into the husks and shells of these nuts.  After much gnawing, the rodents consume the nutrition-packed "meat" inside the shells.
     Gray squirrels bury many black walnuts and hickory nuts a couple inches in the ground to be eaten in winter when food is scarce.  But if some squirrels forget where they buried some nuts, or are preyed on by red-tailed hawks, great horned owls or other predators, some of the nuts they planted have a chance to sprout into young trees.  Over the years, I've pulled many black walnut seedlings from our lawn and garden at home.   
     Other kinds of wildlife, including foxes, opossums, blue jays, American crows, northern cardinals and a small variety of seed-eating birds, have opportunities to ingest the meat of black walnuts and hickory nuts.  Many of those nuts are crushed by passing vehicles on roads and streets, releasing the meat onto the blacktop.  But these forms of wildlife must get off the roads ahead of traffic.
     Shagbark hickory and black walnut trees are characteristic of October in local cropland.  They are picturesque to us, and their nuts are valuable to certain kinds of wildlife through fall and winter.