Ailanthus: The Invasive Tree You Should Never Plant
If you’ve ever encountered a fast-growing tree with large, tropical-looking leaves sprouting up in unexpected places, you might have met ailanthus – and that’s not necessarily a good thing. While this perennial tree might seem like an attractive, quick solution for shade, ailanthus is actually one of North America’s most problematic invasive species.
What is Ailanthus?
Ailanthus, scientifically known as Ailanthus altissima (though often referred to simply as Ailanthus), is commonly called the Tree of Heaven – an ironic name for what many consider a botanical nightmare. This woody perennial tree typically grows as a single-stemmed trunk reaching heights greater than 13-16 feet, though under certain conditions it can develop multiple stems or remain shorter.
Originally native to China and northern Vietnam, this non-native species has established itself across most of the United States and parts of Canada, where it reproduces spontaneously without human help and tends to persist in wild areas.
Where Does Ailanthus Grow?
Unfortunately, ailanthus has spread extensively across North America. You can find this invasive tree growing in Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, and Wisconsin. It’s also established in Ontario and Quebec, Canada.
Why You Should NOT Plant Ailanthus
Here’s the bottom line: ailanthus is a highly invasive species that causes significant ecological damage. While it might seem appealing as a fast-growing shade tree, planting ailanthus is strongly discouraged for several reasons:
- It aggressively outcompetes native plants for resources
- Produces chemicals that inhibit the growth of other plants nearby
- Spreads rapidly through both seeds and root suckers
- Difficult to control once established
- Disrupts natural ecosystems and biodiversity
Growing Conditions and Characteristics
Part of what makes ailanthus so problematic is its incredible adaptability. This tree thrives in USDA hardiness zones 4-8 and tolerates:
- Poor, compacted soils
- Drought conditions
- Urban pollution
- Full sun to partial shade
- Wide range of soil pH levels
The tree features large compound leaves that can give it a tropical appearance, smooth bark, and clusters of small flowers that produce papery, winged seeds. Its extremely fast growth rate – sometimes several feet per year – might seem attractive, but this rapid spread is exactly what makes it so invasive.
Better Native Alternatives
Instead of planting ailanthus, consider these native alternatives that provide similar benefits without the ecological damage:
- Black walnut (Juglans nigra) for large shade
- American basswood (Tilia americana) for fast growth
- Sugar maple (Acer saccharum) for beautiful foliage
- Eastern red cedar (Juniperus virginiana) for adaptability
If You Already Have Ailanthus
If you discover ailanthus on your property, removal is recommended. However, cutting alone often stimulates more vigorous growth from the root system. Effective removal typically requires:
- Professional assessment and treatment
- Combination of cutting and herbicide application
- Long-term monitoring for new growth
- Patience – complete eradication can take several years
The Bottom Line
While ailanthus might look attractive and grow quickly, its invasive nature makes it a poor choice for any garden or landscape. Instead of contributing to the spread of this problematic species, choose native alternatives that will provide beauty and function while supporting local ecosystems. Your garden – and the environment – will thank you for it.
