North America Native Plant

Tilesius’ Wormwood

Botanical name: Artemisia tilesii unalaschcensis

USDA symbol: ARTIU2

Life cycle: perennial

Habit: subshrub

Native status: Native to Alaska  

Synonyms: Artemisia hookeriana Besser (ARHO11)  âš˜  Artemisia tilesii auct. non Ledeb. (ARTI4)  âš˜  Artemisia tilesii Ledeb. var. unalaschcensis Besser (ARTIU)   

Tilesius’ Wormwood: Alaska’s Hardy Native Shrub If you’re gardening in Alaska or other frigid northern climates, you’ve probably struggled to find plants that can truly thrive in your harsh conditions. Enter Tilesius’ wormwood (Artemisia tilesii unalaschcensis), a tough-as-nails native Alaskan shrub that laughs in the face of bitter cold and ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Tilesius’ Wormwood: Alaska’s Hardy Native Shrub

If you’re gardening in Alaska or other frigid northern climates, you’ve probably struggled to find plants that can truly thrive in your harsh conditions. Enter Tilesius’ wormwood (Artemisia tilesii unalaschcensis), a tough-as-nails native Alaskan shrub that laughs in the face of bitter cold and challenging growing conditions.

What is Tilesius’ Wormwood?

This perennial shrub is a true Alaskan native, perfectly adapted to life in the Last Frontier. Don’t let the name wormwood put you off – this isn’t about garden pests! The name comes from the plant’s traditional uses, and this particular species is a beautiful, low-maintenance addition to cold-climate gardens.

Tilesius’ wormwood typically stays compact, usually growing under 1.5 feet tall, though it can occasionally reach up to 3 feet in ideal conditions. Its silvery-gray foliage creates a lovely textural contrast in the garden, and the aromatic leaves add a pleasant fragrance when brushed against.

Where Does It Grow Naturally?

This hardy shrub is native to Alaska, where it has adapted to some of North America’s most challenging growing conditions. You’ll find it growing naturally throughout the state, from coastal areas to interior regions.

Why Choose Tilesius’ Wormwood for Your Garden?

If you’re gardening in USDA hardiness zones 2-6, this plant could be a game-changer for your landscape. Here’s why:

  • Incredibly cold hardy: This plant has evolved to survive Alaskan winters – your garden’s cold snaps won’t faze it
  • Low maintenance: Once established, it requires minimal care and watering
  • Attractive foliage: The silvery-gray leaves provide year-round interest
  • Compact size: Perfect for smaller gardens or as a foundation planting
  • Native plant benefits: Supports local ecosystems and wildlife

Garden Design Ideas

Tilesius’ wormwood works beautifully in several garden settings:

  • Native plant gardens: Pair with other Alaskan natives for an authentic regional landscape
  • Rock gardens: Its compact size and drought tolerance make it perfect for rocky, well-draining areas
  • Ground cover: Plant in masses for erosion control on slopes
  • Mixed borders: Use as a textural element alongside other cold-hardy perennials

Growing Conditions and Care

The beauty of this plant lies in its simplicity. Here’s what Tilesius’ wormwood needs to thrive:

  • Sunlight: Full sun to partial shade
  • Soil: Well-draining soil is essential – this plant hates wet feet
  • Water: Drought tolerant once established; avoid overwatering
  • Climate: Thrives in USDA zones 2-6

Planting and Care Tips

Getting started with Tilesius’ wormwood is straightforward:

  • Plant in spring after the last frost
  • Ensure excellent drainage – amend heavy clay soils with sand or gravel
  • Water regularly during the first growing season to establish roots
  • Once established, water only during extended dry periods
  • Light pruning in early spring helps maintain a tidy shape
  • No fertilizer needed – this plant prefers lean soils

Important Considerations

While this plant has a conservation status rating, the specific meaning is unclear from current data. If you’re interested in growing Tilesius’ wormwood, make sure to source plants responsibly from reputable native plant nurseries. This ensures you’re not impacting wild populations and that you’re getting authentic, locally-adapted genetics.

One challenge you might face is availability. Since this is a specialized native Alaskan plant, it may not be readily available at your typical garden center. You’ll likely need to seek out native plant specialists or botanical gardens with cold-climate collections.

The Bottom Line

Tilesius’ wormwood is a fantastic choice for gardeners in extremely cold climates who want a low-maintenance, attractive native plant. While it may not be the showiest plant in your garden, its reliability, cold hardiness, and subtle beauty make it a valuable addition to northern landscapes. Plus, you’ll be supporting native biodiversity – and there’s something pretty special about growing a plant that calls Alaska home.

If you can get your hands on this hardy little shrub, you’ll have a dependable garden companion that truly understands what it means to weather the storm.

Tilesius’ Wormwood

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Artemisia L. - sagebrush

Species

Artemisia tilesii Ledeb. - Tilesius' wormwood

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