How to Grow Matilija Poppy

The Matilija Poppy, also known as the tree poppy, is native to California and northern Mexico. Its scientific name, Romneya coulteri, takes its inspiration from the name of Dr. Thomas Coulter, the botanist who discovered it. This large white flower has six petals with a ball-shaped center of bright yellow stamens. The petals have a wrinkly, crepey, and delicate texture, but they can withstand strong winds and rain. The flower produces abundant nectar and attracts many bees in spring. It's sometimes called fried egg flower, for its uncanny resemblance to a very large fried egg.

Growing between six and nine feet tall, it thrives in dry, sunny climates and can be found among the unique landscape features of southern California such as dry canyons and even in areas that have suffered from wildfires. It goes dormant in winter and is a deciduous summer plant; the leaves usually start drying out and falling in early autumn. It can be grown as an annual in containers or beds in most places, but will only naturalize where it has suitable growing conditions. Once established, it can become invasive, spreading by a network of rhizomes.

A bit of trivia: In 1890 the matilija poppy was a candidate for the state flower of California, but it was beaten in a vote by the California poppy, which although much smaller comes in a large variety of colors.

Botanical Name	Romneya coulteri
Common Name	Matilija poppy, fried egg plant, California tree poppy
Plant Type	Tender perennial
Mature Size	6 to 10 feet tall
Sun Exposure	Full sun
Soil Type	Sandy loam, tolerant of all soils
Soil pH	5 to 8
Bloom Time	March to August
Flower Color	White
Hardiness Zones	USDA 8 to 10
Native Areas	California, northern Mexico

Matilija Poppy Care

These majestic plants need a lot of space, so make sure you're able to accommodate them before planting in your garden beds. Their tendency to be invasive is also a consideration; planting in containers might be the best bet. If planting nursery plants, be careful while transplanting to handle the roots gently.

Soil

Being native to dry, arid, desert climates, the matilija poppy prefers dry, sandy soil. It requires good drainage, so clay soils might require amendments. Otherwise this flower is fairly tolerant of diverse soil conditions.

Light

To reach their full height and flowering potential, these plants need full sun exposure. They will grow in dappled shade, but the brilliant golden color of the yellow centers is brightest with full sun exposure.

Water

The best watering practice is to try and mimic native desert watering conditions; that is to say, as if an occasional hearty rainfall occurs every few days. Once a week is reasonable, perhaps every five days or so if growing in containers. It's okay to let the soil dry out a bit between waterings, as this plant is very drought resistant. You'll know to give it supplemental water in addition to your regular schedule when the plant starts drooping. Overwatering will cause leaves to discolor and flower petals to fall prematurely. Mulching to ensure even moisture may also be helpful.

Temperature and Humidity

Matilija poppies thrive in dry conditions and warm temperatures. Their hardiness zone is fairly narrow (USDA 8 to 10), which usually indicates a plant that likes very specific growing conditions. If your growing zone hovers between 7 and 8, you might be able to get these to overwinter by mulching them heavily. If you can mimic the plant's native growing conditions, this may be a plant you can enjoy in your yard. But with the matilija poppy, ideal growing conditions also means the plant can become invasive.

Common Pests and Diseases

Matilija poppies are deer resistant, drought-tolerant, and resistant to most pests, though they can be somewhat susceptible to powdery mildew, which can be treated with neem oil. They might also attract various caterpillars who may munch the eaves and breed; this situation can be controlled by using a Bacillus thuringiensis spray, which is non-toxic to humans.