The Story
Plant Bio
Senna artemisioides, commonly known as silver cassia, is an erect, woody evergreen shrub endemic to the arid and semi-arid interior of mainland Australia. It features pinnately compound, silvery-grey foliage covered in fine, silky hairs that give the plant a soft, feathery texture.
Bright yellow, cup-shaped flowers are produced in small clusters from winter through spring, followed by flat, linear brown seed pods. The species is highly adapted to nutrient-poor, well-drained soils and exhibits extreme drought tolerance once established.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Shrub
Height
118 inches
Width
78 inches
Light
Full Sun, Partial Sun
Zones
9, 10
Water
Low
Humidity
Low to Moderate
Lifespan
Moderate
Native To
Australia
Toxicity
Non-toxic
Bloom period
Winter – Spring
In flower about 4 months of the year
Planting
How to Grow
- Select a planting site in full sun with excellent, free-draining sandy, loamy, or gravelly soil.
- Dig a hole twice the width of the root ball and of equal depth, avoiding heavy clay pockets.
- Position the plant at its original soil level, backfill without adding organic matter, and water in lightly.
- Establish the shrub with minimal supplemental watering, transitioning to dry conditions once new growth appears.
Pro Tip
Prune lightly immediately after flowering in late spring to maintain a dense habit; pruning in late summer or autumn removes the wood where winter flower buds have already initiated.
Keep It Thriving
Care Guide
Do
- Plant in a position that receives full sun to maintain a dense, mounding form.
- Ensure the soil drains rapidly to prevent root rot.
- Prune lightly in late spring immediately after the flowering period finishes.
Don't
- Do not overwater during summer or plant in heavy, waterlogged clay soils.
- Do not apply high-nitrogen fertilisers, as this legume fixes its own nitrogen.
- Do not prune hard into old, leafless wood, as it may fail to reshoot.
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Pest Check | ||||||||||||
| Propagate | ||||||||||||
| Prune |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna questions
What zones can Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna grow in?
Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna is hardy in USDA Zones 9–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
When does Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna bloom?
Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna typically blooms in winter through spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna need full sun?
Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna drought tolerant?
Yes — once established (usually after the first full season), Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
Keep exploring
Explore the genus
Hardy in your zone?
Grow Silver Cassia, Feathery Cassia, Wormwood Senna, Silver Senna with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.