The sound of buzzing insects is so loud that it stops you in your tracks during a walk in the woods. Looking around, you find a tree laden with large, 10-12” clusters of small creamy white flowers with every bee, wasp, and fly in the neighborhood buzzing around. Then you notice that there are more trees and more bees, wasps, and flies. The noise is deafening. What is this tree that is so popular with pollinators?
This is the bee-bee tree, Tetradium daniellii, also known as Korean evodia. It grows to 30’ tall with a similar spread and has smooth, dark gray bark with small white lenticels. The compound leaves are opposite with smooth, shiny, dark green leaflets. The tree can be mistaken for young native ash trees (Fraxinus sp.) or tree of heaven (Ailanthus altissima) in all sizes. Ash trees also have opposite leaves; tree of heaven has alternate leaves.
Bee-bee trees are either male or female; that is, the male or female flowers are on separate trees. Both produce large, clustered flower heads. The female flower heads turn a wonderful red as the seeds ripen for a second decorative show. The seeds resemble dark black BB pellets and each female tree produces thousands of seeds. This leads to thick dark stands of bee-bee trees under which few other plants will grow. Even Japanese stiltgrass (Microstegium vimineum) does not grow underneath. The seedling crop is so dense that you can’t move without stepping on seedlings.
Beekeepers love this tree because it blooms in the hot dry part of the summer. As a landowner and beekeeper, I do not like this tree. The tree was planted in arboretums in the mid-Atlantic many years ago and now it is found invading the surrounding areas from its original planting sites. It has invaded several acres on our property and is outcompeting the tree of heaven in that area. This is a feat; it worries me that we will lose even more of our woodlands to these invasive trees.
Bee-bee tree has invaded Michaux State Forest outside of Mont Alto, PA, where it was planted at the Penn State Mont Alto campus, probably the source of our infestation just south of Mont Alto in Maryland. It has also spread around Morris Arboretum, the Virginia State Arboretum at Blandy, VA, and throughout the U.S. National Arboretum in Washington, DC.
Our property is one of three sites being studied by a Towson University graduate student to define the tree’s impact and methods of invasion in our region. We have found the only effective method to treat the invasion is by cutting down the trees and treating the stumps with glyphosate. It will take us years to insure the tree is no longer found on our property. It may be a magnet for bees, however it is suppressing and outcompeting the native plants that our native bees and insects need to survive. We hope others will join us to catch it before it takes over.
Additional Resources
- Should the Bee-Bee Tree be Avoided? | Maryland Invasive Species Council
- Invasive Plants in Pennsylvania: Bee-Bee Tree | Pennsylvania Department of Conservation and Natural Resources
- Introduction to Invasive Plants | University of Maryland Extension Home & Garden Information Center
By Ann Aldrich, beekeeper, native plant expert, small farm owner in Washington County, Maryland
Oh cuss! I hate it when that happens! Seriously, so many of the plants that seem to be native were brought in as ornamentals. Pampas grass, perwinkle, broom, acacia dealbata, blue gum, and the long list goes on and on and on . . .
How on earth can a beekeeper dislike evodia ??
It is majorly detrimental to the ecosystem.
Large patch in Delaware at Killens Pond State Park, campground side.
Thank you Ann for this story. It’s a good example of how invasive species can cause economic and ecological harm to property owners.
That’s too bad. I wonder if there is a use for the tree that is not identified yet, perhaps a medicinal property that could make it a “one man’s trash is another man’s treasure” situation?
Using glyphosate on them in the name of helping the ecosystem…. we need to think holistically! Read the book “Beyond the War on Invasive Species” by Tao Orion.
I live outside West Chester PA. not too far from Maryland. I have multiple, old specimens of this tree in my yard. Today, I found clusters of invading spotted lanternfly on multiple specimens. Did not find any on other plants. Just an FYI.
If there is destruction all around but somebody’s gout feels better, I do not consider that enough reason to sustain this invasive with its possible of burden of spotted lantern fly. As for resembling ailanthus, doesn’t matter to me because ailanthus gets chopped.
Glysphosate? Sorry, there’s one of me against the former owners’ plantation of vines, hedge roses, and euonymus. I severed gleefully for 18 years. Guess who’s winning? The vines, growing vigorously as the garden catalogs say. This year I am adding spray and painting stumps.
Yes, I will go and read as suggested. I will be happy to annihilate them with green tea and kale, or some other PC solution, if it works.
Beekeeper here I’ll share with folks. Sad to hear as I have planted to help during the dearth,August typically aka no nectar flow.
We received one seedling at a beekeepers’ plant exchange about six years ago and have been nursing it along. It is now about 7′ tall, possibly male, since we have not noticed any offspring. Spotted Lantern Fly love it, similar to Tree of Heaven.
Adding to my previous post regarding the Spotted Lantern Fly on our 7′ Bee Bee Tree. I checked yesterday and counted about 75 SLF. I swept as many as I could into a bucket of soapy wanter and squashed 25 more until there were no more to be found. I checked again this afternoon and there were at least 150 SLF on it. I Again brushed as many as possible into the soapy water and squashed 80 more. Yes, I counted. I checked a Tree of Heaven and did not see any there.
How does this tree spread? Has that been studied very much? I know there are male and female versions of the tree. If it is spread by seed it seems like killing off the female trees and leaving only the males (the ones that aren’t producing seeds) could be a good way to keep the tree for the pollinator benefits but prevent it from spreading into an invasive nuisance? If it is also spreading through underground suckers (which I’ve not seen any indication of, in the research I’ve done), then that would be a different situation and alas, it sounds like mass eradication is the only cure.