Eared Watermoss: Why This Floating Fern Should Stay Out of Your Water Garden
If you’re thinking about adding some aquatic plants to your water feature, you might come across eared watermoss (Salvinia auriculata) in your research. But before you even consider it, let’s have a serious chat about why this innocent-looking floating fern is actually a gardener’s nightmare and an ecological disaster waiting to happen.
What Is Eared Watermoss?
Eared watermoss, scientifically known as Salvinia auriculata, is a small floating aquatic fern that gets its common name from the distinctive ear-shaped lobes on its leaves. Don’t let its delicate appearance fool you – this South American native has become one of the most problematic invasive aquatic plants in many parts of the world.
You might also see this plant listed under its synonyms Salvinia natans or Salvinia rotundifolia in older references, but make no mistake – they’re all referring to the same troublesome species.
Where Does It Come From and Where Is It Now?
Originally from South America (specifically Brazil, Argentina, and Paraguay), eared watermoss has hitchhiked its way around the globe. In the United States, it’s established populations in Puerto Rico, where it reproduces freely without any human help.
Why You Absolutely Should NOT Plant Eared Watermoss
Here’s where things get serious. Eared watermoss isn’t just mildly problematic – it’s officially classified as both invasive and noxious in the United States. In Michigan, it’s listed as Invasive, Prohibited, meaning it’s illegal to possess, transport, or sell this plant.
Here’s why this floating fern is such bad news:
- It reproduces incredibly rapidly, doubling its population every few days under ideal conditions
- Forms dense mats that completely cover water surfaces
- Blocks sunlight from reaching underwater plants, killing them
- Reduces oxygen levels in water, harming fish and other aquatic life
- Clogs waterways, making them impassable for boats
- Creates perfect breeding grounds for mosquitoes
How to Identify Eared Watermoss
Since this plant is so problematic, it’s important to know what it looks like so you can report it if you spot it in the wild. Eared watermoss is a small floating fern that forms dense green mats on the water surface. The key identifying feature is the distinctive ear-shaped or heart-shaped lobes on the floating leaves.
As an obligate wetland species, you’ll only find this plant in aquatic environments – it can’t survive on dry land.
What to Do If You Find It
If you discover eared watermoss in your local waterways, don’t try to remove it yourself – you could accidentally spread fragments to new areas. Instead, contact your local environmental authorities or invasive species management office immediately.
Native Alternatives for Your Water Garden
Instead of risking ecological disaster with eared watermoss, consider these beautiful native aquatic plants for your water feature:
- American lotus (Nelumbo lutea) for larger ponds
- Spatterdock (Nuphar advena) for smaller water gardens
- Water lily species native to your region
- Native floating heart varieties
The Bottom Line
Sometimes in gardening, the answer is a hard no, and eared watermoss is definitely one of those times. This aggressive invasive fern might look harmless, but it’s capable of destroying entire aquatic ecosystems. Do your local environment a favor and choose native aquatic plants instead – your local wildlife (and your neighbors) will thank you!
Remember, responsible gardening means considering not just what looks good in your yard, but what’s good for your local ecosystem too. When it comes to eared watermoss, the kindest thing you can do is keep looking for better alternatives.
