Walnuts keep falling on my head…

Nature // October 11, 2015

By Trish Fries, Wissahickon Environmental Center

I have a love/hate relationship with black walnut trees (Juglans nigra). The fruit is fascinating: It looks like a lime and smells citrusy, and the nut is good to eat. But the husk stains anything it touches, and the ripe fruit, when they drop, are like baseballs falling from the sky.

Black walnut tree roots contain juglone, a compound that will prevent many plants species from growing beneath it, so they dominate any area in which they grow. Several black walnut trees surround the Tree House and start dropping their fruit in late summer and continue through October. Every year, before FOW’s Whispers Along the Wissahickon, hours are spent picking up the black walnuts so visitors don’t slip on them in the dark. Although the leaves on the trees are delicate, once summer fades, the falling fruit is messy and heavy enough to dent cars parked under the trees. Luckily, I’ve never had one fall on my head.

Despite all the trouble they cause us at the Tree House, black walnuts tug at my heart strings. As a child, I ate chocolate chip cookies with black walnuts that my grandmother harvested and prepared. Of course I didn’t appreciate the work that was involved in baking them until I tried to show children at the Tree House how to crack the outer shell to get to the meat. Now I admire her perseverance, along with the strength of the squirrels in Andorra. They can chew through the tough shell with ease. In fact, squirrels are the primary consumers of black walnuts; most of us can’t be bothered with the work involved.

If you are willing to take on the challenge of cracking them, the black walnut will reward you with an earthy, sweet flavor that differs from the more familiar English walnut. To prepare walnuts to eat, collect them from the ground, remove the outside messy fruit—don’t forget to wear gloves—wash them off, let them dry out for a couple of weeks, then crack them with a hammer to get to the nut meat. If you can get past the mess and the tough shell, using black walnuts for food or anything else will give you a sense of back-to-nature accomplishment—a lot like making maple syrup, something else we like to make at the Tree House!

Trish Fries is an Environmental Education Program Specialist at the Wissahickon Environmental Center (Tree House) for Philadelphia Parks and Recreation.