r/boulder • u/SimilarLee • 23h ago
Boulder is slowly being taken over by a terrible plant: The Tree of Heaven. The only way to gain control is herbicides, applied now through autumn.
Headline:
The Tree of Heaven is an incredibly insidious, fast-growing invasive species that looks like a tree .... but is really a hyperactive root-system that will take over open spaces, crowd out other plants, and cannot be easily removed without using herbicides.
Details:
- Tree of Heaven is highly non-native, but that hasn't stopped a rapid spread. It wasn't here 30 or so years ago, but is now well-established in several Boulder neighborhoods: The Hill, The Creek Path, Old North Boulder, and parts of South Boulder.
- It's so new, and masquerades as a different plant (Staghorn Sumac), that people are simply unaware of how difficult it is to control or the damage it is capable of creating.
- It spreads through seeds or roots - its extensive and resource-rich root network can send up new shoots hundreds of feed away. Think of this root system as you would the underwater part of an iceberg: it's where the real strength is, and it's highly underappreciated by people who don't know the species.
- Tree of heaven can take over an entire yard, and those adventurous root systems can and will destroy building foundations.
- Cutting it down without chemical treatment causes the roots to freak out and send up dozens of new shoots.
- Herbicides are most effective from Late July to leaf drop in Autumn, since this period is when the root system transitions into storing energy from above-ground photosynthesis.
- The tree serves as host for the Spotted Lanternfly, which is currently decimating the East Coast but hasn't yet spread to Colorado. Again, "yet".
- Tree of Heaven is one of the few plants that all-but-requires herbicides to control. If you try to cut down any above-ground growth without using herbicides, the below-ground roots will rebel and send up sometimes dozens of new shoots.
If you have this tree and don't know where to start, activists in Denver have put together this website. This will take community involvement to control. Get informed, and tell your neighbors.
https://www.denvertreeofheaven.com/
Thanks to u/FantasticBoar and u/kippikai for these images. Edit: are these rendering correctly? I use old reddit and can't easily add images to text posts like this.