North America Native Plant

Little Spleenwort

Botanical name: Asplenium exiguum

USDA symbol: ASEX2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Asplenium fontanum (L.) Bernh. (ASFO6)  âš˜  Asplenium glenniei Baker (ASGL6)   

Little Spleenwort: A Tiny Native Fern with Big Character If you’re looking for a fern that breaks all the rules about what ferns should be, meet the little spleenwort (Asplenium exiguum). This pint-sized native doesn’t want your typical moist, shady fern garden – instead, it thrives in the rocky, dry ...

Little Spleenwort: A Tiny Native Fern with Big Character

If you’re looking for a fern that breaks all the rules about what ferns should be, meet the little spleenwort (Asplenium exiguum). This pint-sized native doesn’t want your typical moist, shady fern garden – instead, it thrives in the rocky, dry crevices that would make most ferns shrivel up and call it quits.

What Makes Little Spleenwort Special

The little spleenwort is a true American native, naturally occurring in the southwestern United States. This perennial fern has earned its little moniker honestly – it typically grows just 2-6 inches tall, making it one of the most compact ferns you’ll encounter. Don’t let its size fool you though; what it lacks in stature, it makes up for in character and resilience.

The plant forms neat, compact tufts of finely divided fronds that emerge from rocky crevices like tiny green fountains. Its delicate, lacy appearance creates an almost ethereal quality that can add unexpected texture to challenging garden spots.

Where You’ll Find It Growing Wild

In nature, little spleenwort calls Arizona home, though it also appears in parts of New Mexico and Texas. This native fern has adapted to life in the most unlikely places – limestone outcrops, rock crevices, and other spots where most plants would struggle to survive.

Is Little Spleenwort Right for Your Garden?

Here’s where little spleenwort gets interesting: it’s definitely not your average garden fern. This plant is perfect for gardeners who:

  • Love rock gardens and alpine plantings
  • Have challenging, well-draining spots that need something special
  • Appreciate unique, native plants with specialized growing requirements
  • Want to create a desert or xeric garden with unexpected elements
  • Collect unusual ferns or native plants

However, little spleenwort might not be the best choice if you’re looking for a low-maintenance groundcover or something to fill large spaces. This is very much a specialty plant for gardeners who enjoy the challenge of growing something truly unique.

Growing Conditions and Care

Little spleenwort thrives in USDA hardiness zones 7-10, making it suitable for warmer climates. The key to success with this fern is understanding that it’s adapted to very specific conditions:

Light: Partial shade to filtered sunlight works best. Too much direct sun can scorch the delicate fronds, while too much shade may cause weak growth.

Soil and Drainage: This is absolutely critical – little spleenwort must have excellent drainage. In nature, it grows in rock crevices where water drains away immediately. Use a very gritty, fast-draining soil mix, or better yet, plant it directly in rock crevices or between stones.

Watering: Less is definitely more with this plant. Water sparingly and only when the soil is completely dry. Overwatering is the fastest way to lose this fern.

Planting Tips for Success

When planting little spleenwort, think like the plant – it wants to live in a crack in the rocks, not a typical garden bed. Here are some strategies that work:

  • Plant it between rocks in a rock garden or stone wall
  • Use a container with exceptional drainage filled with a gritty, mineral-based growing mix
  • Create artificial crevices using stacked stones with soil pockets
  • Add plenty of coarse sand, perlite, or small gravel to regular potting soil to improve drainage

Wildlife and Ecological Benefits

While little spleenwort doesn’t attract pollinators like flowering plants do (ferns don’t produce flowers), it can provide habitat for small insects and contributes to the biodiversity of native plant communities. As a native species, it’s part of the natural ecosystem and supports the web of life in its native range.

The Bottom Line

Little spleenwort isn’t a plant for everyone, and that’s exactly what makes it special. This tiny native fern offers gardeners in suitable climates the opportunity to grow something truly unique – a piece of the American Southwest’s specialized flora. If you have the right conditions and appreciate plants with personality, little spleenwort can be a rewarding addition to your garden.

Just remember: this is a plant that has spent thousands of years perfecting the art of living in rocky crevices with minimal water. Respect its preferences, give it excellent drainage, and you’ll be rewarded with a charming, resilient native fern that’s sure to spark conversations with fellow plant enthusiasts.

Little Spleenwort

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Aspleniaceae Newman - Spleenwort family

Genus

Asplenium L. - spleenwort

Species

Asplenium exiguum Bedd. - little spleenwort

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA