Squirrels: Free Tree Planters

Our neighborhood squirrels proved they are the best tree planters.

fallen trees after 202 Derecho

We lost most of our mature trees in the 2020 Derecho.

An August 2020 derecho tore through Iowa pushing 140-mile-an-hour wind against trees and buildings. Trees by the hundreds of thousands tumbled to the ground. Winding Pathways wasn’t spared. We lost most of our firs, oaks, hickories, and cottonwoods. The devastation in nearby Faulkes Heritage Woods was even worse.

Almost immediately, shocked people took action. Government forestry departments, aided by tree planting nonprofits, and private citizens unleashed their shovels and planted thousands of trees. So did the squirrels. Well, not really. People planted trees.


Squirrel eating nut

Squirrels bury nuts in caches to retrieve them later.

Squirrels planted nuts and acorns.

Then three seasons of drought followed. Once planted, most trees were not tended as they need to be. So, many human-planted trees shriveled in the heat and dryness, while the nuts buried by squirrels sprouted and the new trees were flourishing.

But why?

We have theories.  A human-planted tree seedling needs plenty of moisture to keep its trunk and new leaves hydrated. Sparse roots must pull water from the ground and send it upward. That’s a tough job in a wet year. Come drought it’s nearly impossible.

Squirrels did better. These industrious rodents don’t mean to create new trees. They’re simply storing nuts underground so they have enough fat and protein-rich food to tide them through winter. All they need to do is dig up a nut when hunger calls. Squirrels overfill their larder, burying more tasty nuts than they’ll ever need.  Unfortunate squirrels are eaten by hawks, foxes, owls, or humans, but the nuts they’d buried remain patiently waiting for spring’s warmth to germinate.

Sprouting nuts grow roots able to pull scarce moisture from the soil and send it to new baby leaves poking through the ground.

As we walked through July 2023’s dry woods we sadly see human-planted trees shriveled up and dead, while nearby a new generation of tiny walnut, oak, and hickories is rising from nuts planted by industrious squirrels.

Squirrels Don’t Plant All The Trees

Squirrels are the best friends of nut-bearing trees, but other tree species can’t rely on the furry rodents. Cottonwoods, for example, produce millions of seeds too tiny for squirrel food. So, the trees grow cottony fluff that floats seeds to distant places. If one lands in a patch of moist bear soil a fast-growing cottonwood sprouts. Maples have helicopter-like seeds that whirl a gig away from the parent to sprout a ways away.

Pity the poor Osage Orange tree that grows huge citrus-smelling balls containing hidden seeds. Many folks call them hedge apples.  A tree must get its seeds away from its own shade.  Squirrels do the job for oaks. The wind for cottonwoods. Massive mastodons once munched on Osage Orange hedge apples, wandered off, digested the pulp, and pooped out the seeds. When these massive elephants went extinct the tree lost its partner and saw its native range shrink from much of North America to a tiny spot down south.

Nature provides many ways for trees to reproduce and the results are often superior to what humans can do. We appreciate the squirrels that plant nuts many of which sprout into healthy native trees. Thanks, squirrels!