Species
Isotoma axillarisBlue Star Flower1 other cultivar
The Story
Plant Bio
A low-growing, mat-forming perennial known for its small white flowers and ability to form a dense carpet of foliage.
Unique for its compact growth habit and ability to tolerate a variety of soil types, making it ideal for ground cover in various settings.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Groundcover
Height
12 inches
Width
12 inches
Light
Full Sun, Partial Sun
Zones
9, 10
Water
Moderate
Humidity
Moderate
Lifespan
Perennial
Native To
Australia
Toxicity
Toxic if ingested, skin irritant
Bloom period
Early summer – Late summer
In flower about 3 months of the year
Planting
How to Grow
- Tuck seeds into well-draining soil and lightly cover with soil for germination.
- Mist cuttings regularly to maintain humidity during rooting.
- Transplant seedlings once they establish strong roots, typically after 4-6 weeks.
- Place in a location with full sun to partial shade for optimal growth.
- Water consistently, keeping soil moist but not waterlogged.
- Mulch around plants to retain moisture and suppress weeds.
Pro Tip
Use well-draining sandy soil and avoid overwatering to prevent root rot.
Keep It Thriving
Care Guide
Do
- Water regularly during dry spells 💧
- Prune lightly after flowering to maintain shape ✂️
- Fertilize with a balanced, slow-release fertilizer in spring 🌱
- Monitor for pests and diseases regularly 🧐
Don't
- Avoid overwatering which can cause root rot ❌
- Don’t disturb roots during flowering period
- Refrain from using heavy clay soil that retains excess water
- Never neglect watering during extended droughts
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Plant | ||||||||||||
| Propagate | ||||||||||||
| Prune | ||||||||||||
| Winter Prep |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Multiply
Propagation Methods
Good to Know
Common Questions
Rock Isotome questions
What zones can Rock Isotome grow in?
Rock Isotome 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.
Is Rock Isotome deer resistant?
Yes — Rock Isotome is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Rock Isotome bloom?
Rock Isotome typically blooms in early summer through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Rock Isotome need full sun?
Rock Isotome does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Isotoma to compare
Keep exploring
Explore the genus
Hardy in your zone?
Grow Rock Isotome 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.