Claspleaf Pennycress: A Quick-Growing Annual with Heart-Shaped Charm
If you’ve ever spotted tiny white flowers blooming in early spring followed by distinctive heart-shaped seed pods, you’ve likely encountered claspleaf pennycress (Microthlaspi perfoliatum). This petite annual herb might not win any flashy flower contests, but it has its own unique appeal for gardeners looking for something a little different.
What Is Claspleaf Pennycress?
Claspleaf pennycress is a small annual forb—essentially a non-woody herbaceous plant that completes its entire life cycle in one growing season. You might also see it listed under its former scientific name, Thlaspi perfoliatum. The claspleaf part of its common name comes from how its upper leaves clasp around the stem, creating a distinctive appearance that makes identification easier once you know what to look for.
Where Does It Come From?
Originally from Europe and western Asia, claspleaf pennycress has made itself at home across much of North America. It’s now established in numerous states including Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Missouri, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, Washington, and West Virginia, plus Ontario and Quebec in Canada.
Should You Plant Claspleaf Pennycress?
Here’s where things get interesting. As a non-native species, claspleaf pennycress sits in that gray area where it’s not necessarily harmful, but it’s not contributing to local ecosystems the way native plants do. If you’re drawn to its quick growth and unique seed pods, there’s no urgent reason to avoid it, but consider these points:
Reasons You Might Like It:
- Provides early spring nectar when few other flowers are blooming
- Distinctive heart-shaped seed pods add visual interest
- Extremely low maintenance once established
- Fills in bare spots quickly
- Tolerates poor soils where other plants struggle
Reasons to Think Twice:
- As a non-native, it doesn’t support local wildlife as effectively as native alternatives
- Can self-seed aggressively in ideal conditions
- Short blooming period means limited ornamental value
Growing Claspleaf Pennycress Successfully
If you decide to give claspleaf pennycress a try, you’ll find it refreshingly undemanding. This adaptable little plant thrives in USDA hardiness zones 3-9, though as an annual, it’s more about timing than surviving winter.
Ideal Growing Conditions:
- Light: Full sun to partial shade
- Soil: Tolerates poor, rocky, or disturbed soils
- Water: Drought tolerant once established
- Temperature: Prefers cool weather, often germinating in fall or early spring
Planting and Care Tips:
- Seeds germinate best in cool, moist conditions
- Can be direct seeded in fall or early spring
- Requires minimal fertilization—too much nutrition can make it overly vigorous
- Deadhead spent flowers if you want to prevent excessive self-seeding
- Allow some plants to go to seed if you want it to return next year
Better Native Alternatives
If you love the idea of early spring bloomers with interesting seed pods, consider these native alternatives that will better support your local ecosystem:
- Wild ginger (Asarum canadense) for heart-shaped leaves
- Spring beauty (Claytonia virginica) for early white flowers
- Toothwort (Cardamine species) for similar flower timing and form
- Wild columbine (Aquilegia canadensis) for interesting seed pods
The Bottom Line
Claspleaf pennycress won’t revolutionize your garden, but it might find a place in naturalized areas or as a temporary ground cover while you establish more permanent plantings. Its early flowers can provide nectar when pollinators are desperate for any food source, and those heart-shaped seed pods do have a certain quirky charm.
Just remember that every garden spot occupied by a non-native is a missed opportunity to support local wildlife with a native alternative. If you’re building habitat for butterflies, birds, and beneficial insects, prioritize native species that have co-evolved with your local ecosystem.
