The Story
Plant Bio
Romneya coulteri, commonly known as the California tree poppy, is a perennial plant prized for its striking white flowers and gray-green foliage.
This species is particularly drought-tolerant and thrives in well-drained soils, making it suitable for Mediterranean-style gardens.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
72 inches
Width
48 inches
Light
Full Sun
Zones
7, 8, 9, 10
Water
Low to moderate
Humidity
Low
Lifespan
Perennial
Native To
California and Baja California
Toxicity
Non-toxic
Bloom period
Early summer – Late summer
In flower about 3 months of the year
Marketplace
Where to Buy
Shipping costs Year-round shipping Free shipping
Planting
How to Grow
- Tuck seeds into well-draining soil in early spring for best germination.
- Mist cuttings regularly to maintain humidity and encourage root development.
- Plant in full sun for vigorous growth and flowering.
- Water deeply once a week during dry periods to keep soil moist but not waterlogged.
- Fertilize with a balanced, low-nitrogen fertilizer in early spring and mid-summer.
- Divide established plants in early spring or late fall to promote healthy growth.
Pro Tip
Use well-draining sandy soil to prevent root rot and encourage healthy blooms.
Keep It Thriving
Care Guide
Do
- Water deeply during dry spells 💧
- Prune after flowering to shape the plant ✂️
- Apply mulch to retain soil moisture and suppress weeds 🌱
Don't
- Avoid overwatering to prevent root rot ❌
- Don’t disturb roots during flowering period 🚫
- Refrain from fertilizing with high-nitrogen formulas, which can cause excessive foliage
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deadhead | ||||||||||||
| Plant | ||||||||||||
| Propagate | ||||||||||||
| Prune | ||||||||||||
| Spring Cleanup |
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
Matilija Poppy questions
What zones can Matilija Poppy grow in?
Matilija Poppy is hardy in USDA Zones 7–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Matilija Poppy deer resistant?
Yes — Matilija Poppy is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Matilija Poppy bloom?
Matilija Poppy 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 Matilija Poppy need full sun?
Matilija Poppy does best in full sun (6+ hours).
Is Matilija Poppy drought tolerant?
Yes — once established (usually after the first full season), Matilija Poppy 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 Matilija Poppy 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.