← Plant Guides

How to Grow Grass Tree

Wikimedia Commons

Grass Tree

Xanthorhiza pumila

shrub

A compact, slow-growing Australian native shrub known for its distinctive dark, strap-like foliage and striking yellow flowers. This evergreen perennial is prized for its ornamental appeal and architectural form in gardens.

When should you plant Grass Tree in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Grass Tree timeline →

Example Grass Tree timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Grass Tree

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Grass Tree

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Grass Tree dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily
💧
Water: Drought tolerant once established; water sparingly during first year; reduce watering significantly after establishment to prevent root rot
📏
Spacing: 36 inches
📅
Days to maturity: 1200-1800 days (3-5 years before flowering)
🌱
Planting depth: Surface sow seeds; plant rhizomes 1 inch deep

Soil

Type: Well-draining sandy loam or gravelly soil
pH: 6.5-7.5
Amendments:
Perlite or coarse sand for drainage Gravel mulch to prevent root rot

Growing Zones

Find your zone →

Thrives in zones 9b-11, preferring warm, Mediterranean climates

9b 10a 10b 11a 11b

Sign up free to see if Grass Tree grows in your zone — and get a personalized planting timeline.

Get my Grass Tree timeline →

Growth Stages

1

Seedling

3-6 months

Tiny grass-like shoots emerging from soil with initial narrow leaves

Keep soil lightly moist but not wet; provide bright light; very slow initial growth is normal; patience essential

2

Juvenile

1-3 years

Expanding clump of strap-like dark green leaves forming a low mound; no obvious trunk yet

Gradually reduce watering as plant establishes; ensure excellent drainage; apply minimal fertilizer; light pruning of damaged leaves acceptable

3

Maturing

1-2 years

Plant develops distinct trunk-like base as old leaf bases accumulate; foliage becomes denser and more uniform

Maintain minimal water; do not fertilize; avoid disturbance; mulch base lightly with gravel

4

Flowering

6-8 weeks

Distinctive yellow flower spikes emerge from the center of the leaf crown, followed by small seed capsules

No supplemental care needed; allow seed heads to develop naturally; deadheading is optional

5

Mature

Indefinite (15+ years)

Fully formed plant with clear trunk, dense foliage crown, and regular flowering cycles

Virtually no maintenance required; water only during extreme drought; natural form should be preserved

Companion Planting

Plan your garden →

Plant with:

Silver banksia Desert rose Texas privet Lavender Russian sage Ornamental grasses

Avoid planting near:

Water-loving plants Acid-preferring plants Dense shade-producing trees Plants requiring frequent watering

Common Pests

  • Prevent through excellent drainage; avoid overwatering; remove affected plants immediately to prevent spread

  • Hand removal of affected leaves; horticultural oil spray in early infestation; naturally resistant if plant is healthy

  • Remove affected leaves; improve air circulation; ensure soil dries between waterings

Uses

🎨

Ornamental architecture

Craft

Xanthorhiza pumila serves as a striking focal point in drought-tolerant and xeriscaped gardens, valued for its sculptural form and slow growth that requires minimal maintenance. [source]

🦋

Native pollinator support

Wildlife

The golden-yellow flowers attract native Australian bees and insects, supporting local pollinator populations in appropriate climates. [source]

🏠

Low-maintenance landscaping

Household

Its extreme drought tolerance and lack of fertilizer requirements make it ideal for water-wise gardening and landscapes designed to reduce maintenance labor. [source]

🎨

Contemporary garden design

Craft

Modern landscape designers favor Xanthorhiza pumila for its unique silhouette that creates visual interest and Mediterranean or desert garden aesthetics. [source]

Harvest Tips

Not typically harvested for food or foliage; flowers can be enjoyed in situ; allow seed heads to mature naturally for self-seeding or seed collection

Fun Facts

  • 🌱 Despite its common name 'Grass Tree,' Xanthorhiza pumila is not a grass but a monocot shrub that can live for 50+ years with virtually no maintenance
  • 🌱 The plant grows extremely slowly, sometimes adding less than 1 inch of height per year, making it a living sculpture that develops character over decades
  • 🌱 In its native Australian habitat, it survives intense droughts and fires; the dense leaf base provides insulation and the plant can resprout after fire damage

Gardening Terms

New to gardening? Learn about terms used in this guide:

Crown Deadhead Full Sun Mulch Perennial
Shop Grass Tree plants and related plants at Plant Addicts →

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Grass Tree planting timeline

Tell us your zip code and we'll calculate exactly when to start Grass Tree seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Grass Tree timeline →