North America Native Plant

Slimspike Threeawn

Botanical name: Aristida longespica var. longespica

USDA symbol: ARLOL3

Life cycle: annual

Habit: grass

Native status: Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Aristida gracilis Elliott (ARGR13)  âš˜  Aristida longispica Poir. var. longispica Poir., orth. var. (ARLOL2)   

Slimspike Threeawn: A Delicate Native Grass for Natural Landscapes Meet the slimspike threeawn (Aristida longespica var. longespica), a charming annual grass that’s perfect for gardeners looking to add authentic native texture to their landscapes. This slender beauty might not be the showiest plant in your garden, but it brings something ...

Slimspike Threeawn: A Delicate Native Grass for Natural Landscapes

Meet the slimspike threeawn (Aristida longespica var. longespica), a charming annual grass that’s perfect for gardeners looking to add authentic native texture to their landscapes. This slender beauty might not be the showiest plant in your garden, but it brings something special to naturalistic plantings with its graceful, airy appearance and important ecological benefits.

What Makes Slimspike Threeawn Special?

As its common name suggests, this native grass is characterized by its slim profile and distinctive three-awned seed heads that dance gracefully in the breeze. The threeawn part of its name comes from the three bristle-like projections (awns) that extend from each seed, creating an almost feathery appearance that adds wonderful texture to natural gardens.

This annual grass typically grows 1-3 feet tall with a narrow, upright habit that won’t overwhelm other plants in mixed plantings. Its fine-textured foliage and delicate seed heads create beautiful contrast when planted alongside broader-leaved native wildflowers and other prairie plants.

Native Status and Geographic Distribution

Slimspike threeawn is a true North American native, naturally occurring across a remarkably wide range that includes both Canada and most of the lower 48 states. You’ll find this adaptable grass growing wild from the southeastern provinces of Canada down to the Gulf Coast states, and from the Atlantic seaboard west to the Great Plains.

Specifically, it grows naturally in Alabama, Arizona, Arkansas, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Washington, West Virginia, Wisconsin, and the District of Columbia, plus Ontario, Canada.

Why Choose Slimspike Threeawn for Your Garden?

Here are compelling reasons to consider adding this native grass to your landscape:

  • Low maintenance: As an annual, it completes its life cycle in one season and readily self-seeds in suitable conditions
  • Drought tolerant: Once established, it requires minimal watering
  • Wildlife value: Seeds provide food for songbirds and small wildlife
  • Soil adaptable: Thrives in both sandy and clay soils that challenge other plants
  • Natural movement: Adds graceful motion to the garden as it sways in breezes
  • Native authenticity: Supports local ecosystems and native plant communities

Perfect Garden Settings

Slimspike threeawn shines brightest in naturalistic settings where its subtle beauty can be appreciated. Consider it for:

  • Prairie and meadow gardens
  • Native plant landscapes
  • Wildlife habitat areas
  • Low-maintenance naturalized spaces
  • Mixed grass plantings
  • Erosion control on slopes

Growing Conditions and Care

One of the best things about slimspike threeawn is how easy it is to grow. This adaptable grass thrives in USDA hardiness zones 3-9, making it suitable for most North American gardens.

Ideal Growing Conditions:

  • Sunlight: Full sun (6+ hours daily)
  • Soil: Adaptable to various soil types, including poor soils
  • Moisture: Drought tolerant once established
  • pH: Tolerates a wide range of soil pH levels

Planting and Care Tips

Getting started with slimspike threeawn couldn’t be simpler:

  • Seeding: Direct seed in fall or early spring when soil temperatures are cool
  • Planting depth: Barely cover seeds with soil – they need light to germinate
  • Spacing: Allow natural spacing through broadcasting or plant every 6-12 inches
  • Watering: Keep soil moist until germination, then water sparingly
  • Maintenance: Minimal care required – let plants complete their natural cycle

A Few Considerations

While slimspike threeawn is generally wonderful, keep these points in mind:

  • As an annual, it will need to reseed each year (though it does this naturally)
  • Its subtle appearance might not satisfy gardeners seeking bold, showy plants
  • Best appreciated in mass plantings rather than as individual specimens

The Bottom Line

Slimspike threeawn is an excellent choice for gardeners who appreciate native plants and want to create authentic, low-maintenance landscapes that support local wildlife. While it may not have the flashy flowers of showier natives, its graceful form, ecological benefits, and effortless growing habits make it a valuable addition to naturalistic gardens across much of North America.

Whether you’re establishing a prairie garden, creating wildlife habitat, or simply want to add some authentic native texture to your landscape, slimspike threeawn deserves a place in your planting plan. Once you see how beautifully it moves in the breeze and how eagerly birds seek out its seeds, you’ll understand why this humble grass has earned its place in the native gardener’s toolkit.

Slimspike Threeawn

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Cyperales

Family

Poaceae Barnhart - Grass family

Genus

Aristida L. - threeawn

Species

Aristida longespica Poir. - slimspike threeawn

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