Data provided by the participants of the Consortium of California Herbaria

View additional distribution information on the Jepson eflora

Coulter's Matilija Poppy (Romneya coulteri) is one of the largest and showiest California poppies. Large white petals with a crinkled texture surround yellow stamens, giving this poppy a bright, cheerful appearance. Its flowers, which can be as large as 7 inches across, are attractive to bees and butterflies.


This plant can be challenging to establish, as it can suffer from both too much and too little water. Once established, however, it readily spreads by rhizomes and can soon outgrow its intended area. (Pulling shoots usually suffices to control it.) Plant in full sun in well-draining, sandy soil. Matilija Poppy is a low-water plant that does not need supplemental summer irrigation once established.

Plant type

Perennial herb

Size

7 - 10 ft Tall
20 ft Wide

Form

Upright Columnar, Weeping

Growth rate

Moderate

Dormancy

Summer Deciduous

Fragrance

None

Calscape icon
Color

Yellow, White

Flowering season

Summer, Spring

Special uses

Deer resistant, Groundcover

Sun

Full Sun

Water

Very Low, Low

Summer irrigation

Never irrigate once established

Ease of care

Easy

Cold tolerance

Tolerates cold to -6° F

Soil drainage

Fast, Medium

Soil description

Prefers sandy or gravelly soil with fast drainage.
Soil PH: 5.0 - 8.0

Maintenance

It is advisable to cut down to 6 inches in late Summer or Fall. Dried leaves and stalks make excellent mulch when chopped or broken up

Propagation

Usually by rhizomes during winter. Disturbing the rhizomes at other times is usually fatal. Propagation by seeds is difficult.  For propagating by seed: Fire treatment in late fall and germinate outdoors; or soak in l N potassium hydroxide (KOH) 1/2 hr., then soak in 100 ppm GA3 overnight. Soaking in KOH followed by 3 mos. stratification, then GA3 may improve germination ( Harrington 1975). 3 mos. stratification gives some germination.

Sunset Zones

4*, 5*, 6, 7*, 8*, 9*, 10, 11, 12, 14*, 15*, 16*, 17*, 18*, 19*, 20*, 21*, 22*, 23*, 24*

Site type

Dry washes, canyons and foothills, with chaparral or coastal sage scrub vegetation

Plant communities

Chaparral, Coastal Scrub, Lowland Chaparral, Southern Coastal Scrub

Caterpillars
Butterflies

Butterflies and moths supported

0 confirmed and 1 likely

Confirmed Likely

Neoterpes edwardsata