Honey locust can have large and terrifying thorns making it one of our spookiest native trees.

Images of witches, skeletons, and other specter abound this time of year.  But we really don’t need to look much beyond the natural world for a dose of spooky entertainment? This week, I’ve compiled my list of the top four spookiest native trees that all offer some great Halloween-related attributes everyone can enjoy on All Hallows’ Eve.

Persimmon (Diospyros virginiana) comes in at number four on the list with its large, orange fruits and dark black, blocky bark.  This native offers a canopy full of pumpkin-orange colored fruits each fall that have always put me in the Halloween spirit.  They are delicious and juicy when ripe, with many folks eating them right off the tree or using them in baked goods, jellies, and jams.  However, these delicious fruits have a sinister side if harvested too early and a bite into an unripe persimmon is an eerie experience. The unripe fruit is astringent and leaves a hard to describe wax-like or furry coating in your mouth.

Another native with recognizable fruits enters my list next at number three.  Black cherry (Prunus serotina) has tiny fruits that are a favorite among native birds, providing food for over three dozen species throughout the year.  However, these sought-after fruits, along with leaves, are typically gone by Halloween time, leaving a dead looking, bare tree with burnt-looking, black bark.  Many times cherry trees have a turning and twisting growth habit adding additional creepy appeal. 

Beyond appearances, this tree has an especially dark side when limbs are broken and leaves begin to wilt.  In damaged leaf tissue, two normally separate compounds can combine to form a cyanide-like toxin that can be lethal if grazing animals consume the damaged, wilted leaves.  It’s shockingly spooky to think that one tree can kill an entire cow simply with leaves.

Honey locust (Gleditsia tricanthos) is next on the list due to its large and formidable thorns.  While most wild specimens have a trunk full of these thorns, urban trees typically do not since thornless varieties (var. inermis) of this plant exist.  Honey locust trunks develop large, branched thorn structures that can be up to a foot or more in length at maturity.  They are believed to be a defense mechanism, but their terrifyingly large size exceeds the needs for defense from many fauna that use the tree today.  It is believed that these thorns evolved to defend this tree from grazing megafauna, like mastodons, in prehistoric times.

For today’s fauna a wound from one of these giant thorns can be quite painful. While some believe there is a toxin associated with thorns, I have yet to see any science to prove that point.  However, wounds are often quite painful simply due to the fact that puncture wounds cause significant pain and often leave behind bits of material to further infections.  I know of several arborists over the years who have sustained serious injury from honey locust thorns, sometimes causing enough swelling to immobilize joints.  So, beware of these ominous plant parts unless you have a mastodon-sized tolerance for pain.

Finally, the number one spookiest native tree on my list is black walnut (Juglans nigra).  This tree has a ghastly appeal every Halloween since it is always bare.  It is one of the earliest native trees to lose its leaves, revealing a canopy full of grenade-sized nuts ready to drop on unsuspecting trick-or-treaters if aided by some Halloween wind gusts.   

However, the risk to humans is not the spookiest quality this plant brings to the natural world.  To me, its scariest feature lies in its ability to sway plant populations by effectively killing competing vegetation with a toxic compound.   Black walnut, and other members of the Juglandaceae family, produce a toxin called juglone.  It is present in leaves, roots, nut husks, and bark of these plants. 

By concentrating this compound in the soil over time, walnuts can kill competing vegetation to alter the understory environment.   This creates a plant community under walnut trees that is composed of plants tolerant of juglone.  While many native species are tolerant of juglone, many ornamentals are not, making it especially important to do some research before planting anything close to a walnut.  This characteristic has earned black walnut the number one slot on my list since juglone has the ability to kill more species than any other tree discussed herein.  In addition, it is a nearly invisible, deadly tool that often goes undetected, adding to the frightening allure.

As you celebrate Halloween today, don’t forget that many of our native trees have spooky lore that can add to your holiday.  You might be surprised how many of these menacing plants are lurking nearby.

 

For some related information, see these past Garden Scoop Blog Posts:

Black Walnut – August 23, 2019

Poisonous Plants – August 22, 2018