What Is It About Box Elder?

Box elder planted in a yard (photo by Tom DeGomez, University of Arizona, Bugwood.org)

13 July 2021

In Pittsburgh we hardly think about box elder (Acer negundo). It’s a native tree that grows by the river. No one plants it. It’s not a “bad” tree. So I was puzzled by this 1950’s story from my mother.

I never hear of box elder that I don’t think of your grandfather.  He never had a bad word to say about anyone.  He was a man of integrity and the absolute worst thing I ever heard him say was [this] about a member of the town council: “He was the kind of man who would plant box elder.”

— 1950’s family anecdote from my mother

My grandfather lived in a village in suburban Chicago in the heart of the Midwest where box elder is considered bad, ugly, weedy and invasive. Wikipedia provides this insight on how it got a bad reputation:

“After World War II, box elder’s rapid growth made it a popular landscaping tree in suburban housing developments despite its poor form, vulnerability to storm damage, and tendency to attract large numbers of box elder bugs. … It can quickly colonize both cultivated and uncultivated areas. … It grows around houses and in hedges, as well as on disturbed ground and vacant lots.”

In Wisconsin box elder is so disdained that the Urban Ecology Center wrote a blog in defense of it: Native Tree Spotlight: In Defense of Box Elder.

Box elder isn’t invasive in Pittsburgh so I had to go look for it on its home turf at Duck Hollow. There I found that as a shade tree it can look pretty good. This one is two box elder trunks intertwined.

A large double-trunk box elder shading the bike trail at Duck Hollow, 11 July 2021 (photo by Kate St. John)

However some of them die back leaving ugly bare branches at the top.

Box elder dying back, Duck Hollow, 11 July 2021 (photo by Kate St. John)

And if you cut box elder or chop it down it grows suckers from every crevice.

Midwesterners agree that box elder is bad. Why don’t Pittsburghers have this aversion? I think it’s because we are on the eastern edge of box elder’s range, we never planted it as a street tree, and it isn’t particularly invasive here.

Box elder range map (image from Wikimedia Commons)

What is invasive here? Japanese knotweed! Originally planted as an ornamental, we don’t think it’s pretty anymore.

Japanese knotweed has taken over large portions Duck Hollow, 11 July 2021 (photo by Kate St. John)

If my grandfather had lived in Pittsburgh perhaps he would have said “He was the kind of man who would plant Japanese knotweed.”

Aha. Now I get it.

p.s. Later this summer box elder bugs will appear though not in huge numbers at Duck Hollow.

Box elder bug (photo by John English)

(photo at top by Tom DeGomez, University of Arizona, Bugwood.org, remaining photos by Kate St. John and John English)

11 thoughts on “What Is It About Box Elder?

  1. Young box elder – just sprouting – looks a lot like Poison Ivy. Be careful when pulling that it is actually Box Elder and not Poison Ivy. A mistake could cause lots of grief

  2. Wow!
    There are 285 species of Lepidoptera (moths and butterflies) that depend on box elder to survive their caterpillar stage.

    From the urban forester article.

  3. Another box elder story from my mother: My Uncle George lived in Stowe, VT where box elders sprouted right next to the foundation of his house. He cut them back over and over but the stubs sprouted prolifically. And they were ugly.

    1. We just had an enormous Box Elder cut down in our back yard. It’s trunk was a 17’ circumference. It had three huge leads over our house. It was magnificent and a fun climbing tree for my children. A wonderful shade tree but it had to be done. Every storm that passed over with high winds I would just hope and pray it didn’t drop on my house. It really was a sight to behold and towered over every tree in my town.

    2. I have a box elder growing under a yew by the steps. I’ve been cutting it for 30 years when it starts to invade the steps and it comes back every year.

  4. I have lots of box elder here in Washington County. I leave it alone unless it gets in my way. The bugs it attracts feed the birds and I am good with that!!

  5. My brother feels the same way about black locust. It’s not the most attractive tree, especially when it is growing in a fairly heavily wooded area where it only has branches at the top, but I love the flowers.

    1. Black Locust, a member of the pea family, fixes the nitrogen in the soil and makes it available for other trees and plants.

  6. I was surprised the last time I was in Colorado how common Box Elder is there. I didn’t check the range of the tree at the time so I was unaware how far west it ranges. It’s quite widespread there.

    What about Silver Maple? It too grows along the rivers but where I grew up it seemed to be planted in backyards commonly. It was in my yard before I was born and my parents told me they had theirs cut down and due to rot. I still see it in backyards in older neighborhoods in the Pittsburgh area. I wonder if it was a desired landscape tree back in the 1940s and 1950s or prior. At my childhood home a neighbor had two and they were impressively enormous. They towered over the homeowner’s three story house. They attracted almost any passing bird.

    1. Mike, my mother pointed out that silver maple was the quick-growing tree of choice in Pittsburgh. When I looked for box elders at Duck Hollow I found more silver maples than box elders. Aha!

Leave a Reply to Bruce Huber Cancel reply

Your email address will not be published. Required fields are marked *