Hydrocotyle: The Charming Pennywort That Loves Wet Feet
If you’re looking for a ground cover that thrives where other plants fear to tread—namely in soggy, waterlogged spots—hydrocotyle might just be your new best friend. This unassuming little perennial goes by the charming common name of pennywort, thanks to its distinctive round, coin-shaped leaves that look like nature’s own currency scattered across the ground.
What Exactly Is Hydrocotyle?
Hydrocotyle is a perennial forb, which is a fancy way of saying it’s an herbaceous plant without woody stems that comes back year after year. Think of it as the botanical equivalent of that friend who’s always ready to sprawl out wherever there’s space—in this case, across moist soil with its creeping stems and those adorable penny-shaped leaves.
The plant produces small, delicate flowers in tiny clusters called umbels. These blooms are typically white or greenish and, while not showy, they add a subtle charm to the plant’s overall appearance.
Where Does Hydrocotyle Call Home?
Here’s where things get interesting with hydrocotyle—its native status is a bit of a mixed bag. It’s native to Canada and Puerto Rico, and has been introduced to Hawaii where it now reproduces on its own in the wild. In the lower 48 states, its native status is undefined, which means different species within the genus may have different origins.
You can find hydrocotyle growing across an impressive range of locations, from Alabama to Wisconsin, and from Arizona to Maine. It’s also found in several Canadian provinces including Ontario, Quebec, and the Maritime provinces.
Why You Might Want Hydrocotyle in Your Garden
Hydrocotyle shines in specific situations where other plants struggle:
- Wet problem areas: That soggy spot in your yard where nothing else will grow? Hydrocotyle might thrive there.
- Water garden edges: It creates a natural-looking border around ponds and water features.
- Rain gardens: Perfect for areas designed to capture and filter stormwater runoff.
- Woodland gardens: Provides gentle ground cover in naturalistic settings.
The Pollinator Connection
While hydrocotyle’s flowers won’t stop traffic, they do their part for local ecosystems. The small blooms attract tiny pollinators like small flies and gnats, contributing to the intricate web of garden biodiversity.
Growing Conditions and Care
Hydrocotyle is refreshingly low-maintenance once you understand its preferences:
- Moisture: Loves consistently moist to wet soil—think bog-like conditions
- Light: Adaptable from partial shade to full sun
- Soil: Not picky about soil type as long as it stays moist
- Hardiness: Generally hardy in USDA zones 4-10, though this can vary by species
A Word of Caution
Here’s the thing about hydrocotyle—it can be an enthusiastic spreader. Once it finds conditions it likes, it may colonize areas more aggressively than you initially planned. This makes it excellent for filling large areas quickly, but potentially problematic in more controlled garden settings.
Since its native status varies by location and some species can be quite vigorous, consider starting small to see how it behaves in your specific garden conditions.
Planting and Propagation Tips
Getting hydrocotyle established is typically straightforward:
- Plant in consistently moist soil in spring or fall
- Space plants according to how quickly you want coverage—closer spacing fills in faster
- Water regularly until established (though this is rarely an issue given its moisture preferences)
- Divide clumps every few years if needed to control spread or create new plantings
The Bottom Line
Hydrocotyle is one of those plants that’s perfect for the right situation. If you have consistently wet areas that need covering, or you’re creating naturalistic water features or rain gardens, it could be exactly what you’re looking for. Just go into the relationship knowing that it might love your garden a little too much and be prepared to manage its enthusiasm accordingly.
Before planting, check with your local native plant society or extension office to learn about native alternatives in your area, especially if you’re uncertain about hydrocotyle’s native status in your specific region.
