Tough mulberry tree yields sweet berries, sticky sap

As a youngster, I enjoyed reading Dr. Seuss's "And to Think That I Saw It On Mulberry Street." I was an adult before I learned that actual mulberry trees were just outside my house.

We have two species, one red and one white, one native and one introduced. Both are wildlife favorites, and both probably grow in your neighborhood. So, let's take a walk down our local Mulberry Street.

Red mulberry is our indigenous mulberry. It can be found growing in moist woodlands across Illinois. Red mulberry is a medium-sized tree that can reach a height of 50 feet with a diameter of two feet. Its broad, rounded crown makes red mulberry a useful shade tree.

Both red and white mulberry trees are named after the color of their fruit, but be forewarned: When red mulberries are red, they are NOT ripe. Do not eat unripened berries

The tasty mulberries are ripe when they are purple-black, like a blackberry. When reaching for that first juicy handful, remember that a ripe mulberry easily crumbles in your soon-to-be purple palm.

Not just humans enjoy a handful of sweet mulberries, but wildlife dines on mulberry street as well. A partial list of birds enjoying a midsummer meal of mulberries would include American robin, gray catbird, wood duck, Baltimore oriole, northern cardinal, cedar waxwing, plus red-bellied and redheaded woodpeckers.

Some mulberry munching mammals include opossum, raccoon, fox, skunk, an assortment of squirrels, plus a few dogs I know.

Now that I think of it, it doesn't matter to hungry animals if the berries are red or white. Like its red counterpart, white mulberry is a medium-sized tree. It was introduced to North America during colonial times. It now grows across most of Illinois. White mulberries will thrive in almost any upland habitat, being particularly at home in urban environs.

If you break the leafstalk of a white mulberry, milky sap exudes. This "Elmer's" goo is the foundation of a multicultural exchange that dates back centuries.

Domesticated Chinese silkworm caterpillars feed on white mulberry leaves and then spin large cocoons made of the finest silk that was desired by traders around the world. This led to the ancient and famed Silk Road, a trade route that stretched from China to Europe.

It was hoped Chinese silkworms might adapt to our red mulberry. Their leaves, though, were too tough for the imported caterpillars. Soon, tens of thousands of Asian white mulberries were planted by nurserymen in colonial Virginia. Ben Franklin, George Washington and Thomas Jefferson were among the people who grew these promising saplings.

Unfortunately, that effort at producing silk did not succeed and the neglected white mulberry trees fed birds and mammals who, in turn, spread white mulberry seeds.

Mulberries turned out to be good street trees. Once established, they can withstand salt, drought, air pollution, and soil compaction. There is probably little need to plant mulberries, as wild animals are doing a fine job at that.

This summer, when the berries coat your lawn, it may feel like you have gooey tape on the soles of your shoes.

So, enjoy the Fourth and celebrate the red, white and goo!

• Mark Spreyer is executive director of the Stillman Nature Center in Barrington. Email him at

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