Small-Leaf Climbing Fern: A Beautiful but Dangerous Invader You Should Never Plant
Sometimes the most gorgeous plants can be the most troublesome, and the small-leaf climbing fern (Lygodium microphyllum) is a perfect example of this gardening conundrum. While this delicate-looking fern might seem like an attractive addition to your landscape, it’s actually one of the most problematic invasive species you could encounter – and definitely not something you want anywhere near your garden!
What Exactly Is Small-Leaf Climbing Fern?
The small-leaf climbing fern is a perennial climbing fern with an almost deceivingly delicate appearance. Despite being classified as a forb herb (a vascular plant without significant woody tissue), this fern has twining stems that can climb and spread extensively. Its small, oval leaflets are arranged on pinnately divided fronds, creating what might initially appear to be an elegant, lacy texture.
In Palau, this plant is known as osuchedechui, giving us a hint about its true native origins in the Pacific Basin region, excluding Hawaii.
Where Does It Come From and Where Is It Now?
Originally native to tropical regions of Africa, Asia, Australia, and various Pacific islands, the small-leaf climbing fern has unfortunately made itself at home in places where it absolutely doesn’t belong. In the United States, you’ll currently find established populations in Florida, Guam, and Palau.
Why This Plant Is Gardening Enemy #1
Here’s where things get serious – this innocent-looking fern is classified as invasive in North America and carries noxious weed status in multiple locations:
- Invasive status across North America
- Noxious weed classification in the United States
- Class A noxious weed status in Alabama (the most serious category)
What makes this fern so problematic? It reproduces spontaneously in the wild without any human help and tends to persist once established. In Florida’s delicate wetland ecosystems, it has become a nightmare, smothering native vegetation and completely altering natural habitats.
Where It Thrives (Unfortunately)
The small-leaf climbing fern shows different preferences depending on the region. In the Atlantic and Gulf Coastal Plain, it has facultative wetland status, meaning it usually grows in wetlands but can also survive in drier areas. Interestingly, in Hawaii, it’s classified as an obligate upland plant, almost never occurring in wetlands there.
This adaptability to various moisture conditions is part of what makes it such a successful invader – it’s not picky about where it grows!
Growing Conditions (That You Should Never Provide!)
While we absolutely don’t recommend growing this plant, understanding its preferred conditions can help you identify and remove it if you encounter it:
- Thrives in USDA hardiness zones 9-11
- Prefers warm, humid climates
- Tolerates both wetland and upland conditions
- Grows well in full sun to partial shade
- Adaptable to various soil types
What About Wildlife and Pollinators?
As a fern, the small-leaf climbing fern reproduces through spores rather than flowers, so it provides no benefits for pollinators like bees and butterflies. Any wildlife benefits are far outweighed by the ecological damage it causes to native plant communities that actually support local wildlife.
The Bottom Line: Just Say No
We cannot stress this enough: do not plant small-leaf climbing fern under any circumstances! Its invasive and noxious status means it’s not just a bad garden choice – it’s an ecological threat that can cause serious environmental damage.
If you’re looking for attractive climbing or trailing plants for your garden, consider native alternatives that will provide beauty without the ecological baggage. Your local native plant society or cooperative extension office can suggest wonderful native ferns and climbing plants that will give you the look you want while supporting local ecosystems.
Remember, the best gardens are those that work in harmony with nature, not against it. When it comes to small-leaf climbing fern, the kindest thing you can do for your local environment is to keep it far, far away from your landscape!
