Spadeleaf: The Creeping Herb That’s Taking Root in American Gardens
If you’ve been searching for a unique ground cover that doubles as an edible herb, you might want to get acquainted with spadeleaf (Centella asiatica). This creeping perennial has been quietly making its way into gardens across warmer parts of the United States, and it’s got some interesting qualities that might surprise you.
What Exactly Is Spadeleaf?
Spadeleaf, also known by its botanical name Centella asiatica, is a low-growing perennial herb that belongs to the carrot family. Don’t let that fool you though – this little plant looks nothing like a carrot! Instead, it produces small, kidney-shaped leaves that seem to hover just above the ground on delicate stems. The spadeleaf common name comes from the distinctive shape of these rounded leaves.
This creeping herb is what botanists call a forb – essentially a soft-stemmed plant without woody growth that keeps its growing points right at or below ground level. It’s perfectly designed for hugging the earth and spreading outward.
Where Does Spadeleaf Come From?
Here’s where things get a bit complex. Spadeleaf isn’t native to most of the United States. It’s originally from the wetlands of Asia, Australia, and various Pacific islands. However, it has naturalized in several U.S. locations, meaning it now reproduces on its own in the wild in places like Florida, Hawaii, and Oregon, as well as the territories of Guam and Palau.
While it’s established itself in these areas, it’s important to note that spadeleaf is considered non-native to both Hawaii and the continental United States. If you’re passionate about supporting local ecosystems, you might want to consider native ground covers instead, such as wild ginger in Hawaii or native sedges in other regions.
What Does Spadeleaf Look Like in the Garden?
Spadeleaf has a distinctive appearance that makes it easy to identify. The plant stays quite low – typically reaching only 2-6 inches in height – but can spread 12-18 inches wide through underground runners. Its most notable features include:
- Small, rounded kidney-shaped leaves about 1-2 inches across
- Bright green foliage that forms dense mats
- Tiny clusters of pink or white flowers that appear on short stalks
- A creeping growth habit that fills in spaces quickly
The flowers are quite small and delicate – you might miss them if you’re not looking closely. They appear in small umbels (umbrella-like clusters) and can attract tiny beneficial insects, though they’re not major pollinator magnets.
Where Can You Grow Spadeleaf?
Spadeleaf is only suitable for warm climates, thriving in USDA hardiness zones 9-11. If you live in cooler areas, you could potentially grow it as an annual or in containers that you bring indoors during winter.
This plant has a facultative wetland status, which means it’s equally happy in wet or moderately dry conditions. This flexibility makes it adaptable to various garden situations, from rain gardens to regular flower beds.
How to Grow Spadeleaf Successfully
If you decide to give spadeleaf a try, here’s what you need to know:
Growing Conditions
- Light: Partial shade to full sun (though it appreciates some afternoon shade in hot climates)
- Soil: Moist, well-draining soil rich in organic matter
- Water: Consistent moisture – never let it completely dry out
- Humidity: Prefers high humidity environments
Planting and Care Tips
Spadeleaf is refreshingly low-maintenance once established. Plant it in spring after the last frost, spacing plants about 12 inches apart (they’ll fill in quickly). Keep the soil consistently moist, especially during the first few weeks as the plants establish.
The plant spreads through runners, so it can fill in bare spots relatively quickly. This spreading habit makes it excellent for erosion control on slopes or in areas where you want fast coverage. However, keep an eye on it in small gardens, as it can outcompete more delicate plants.
In container gardens, spadeleaf makes an interesting addition to herb collections or as a trailing element in mixed plantings. Just make sure the container has good drainage while still retaining some moisture.
Garden Design Ideas
Spadeleaf works well in several garden settings:
- Herb gardens: Traditionally used in cooking and medicine
- Rain gardens: Its wetland tolerance makes it perfect for managing runoff
- Container gardens: Great for adding texture to mixed plantings
- Ground cover: Fills in difficult spots where grass won’t grow
- Bog gardens: Thrives in consistently moist conditions
Should You Plant Spadeleaf?
The decision to grow spadeleaf depends on your gardening goals and location. If you live in zones 9-11 and are looking for an unusual, low-maintenance ground cover that can handle both wet and moderately dry conditions, spadeleaf could be a good fit. It’s particularly useful in challenging spots where you need quick coverage.
However, if supporting native ecosystems is a priority for you, consider exploring native alternatives first. Many regions have beautiful native ground covers that provide similar benefits while supporting local wildlife and maintaining ecological balance.
If you do choose to grow spadeleaf, be mindful of its spreading nature and consider it for areas where you want it to naturalize rather than in formal garden beds where precise control is important.
Whatever you decide, remember that the best garden is one that brings you joy while working harmoniously with your local environment. Spadeleaf might just be the quirky ground cover that fits perfectly into your garden story – or it might inspire you to discover an equally interesting native alternative.
