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Mexican Petunia

Ruellia brittoniana

true

1 gallon; 3 gallon

Mexican Petunia

In stock

4'x4'

Sizes:

Mexican Petunia – Ruellia brittoniana

Also known as: Mexican Bluebell, Britton’s Wild Petunia, Purple Showers, Mexican Ruellia

Mexican Petunia is a fast-growing, herbaceous perennial with dark green, lance-shaped leaves and vibrant tubular flowers in shades of purple, pink, or white. Blooming prolifically from spring through fall, the blossoms are a magnet for butterflies and bees. Though it resembles true petunias, it is in the acanthus family and unrelated botanically.

This species is native to northeastern Mexico, but is now widely cultivated and naturalized in the southeastern United States and parts of California. It spreads via rhizomes, forming dense patches where moisture is available. In landscapes with ample irrigation, it can spread aggressively—so site placement and water management are important considerations. In drier desert areas, it behaves more conservatively, especially when planted in part shade or containers.

Mexican Petunia is not frost-tender and can bounce back after light freezes. It thrives in full sun to part shade and tolerates a wide range of soils, including heavy clay. It works well in pollinator gardens, borders, and containers. In desert gardens, some afternoon shade is recommended to prevent leaf scorch and prolong bloom time.

Wildlife Value
Host Plant: —
Nectar Source: Butterflies, including Monarch (Danaus plexippus)
Bird Resources: Insects
Bird Species: Hummingbirds (Trochilidae spp.)

Plant Care

Native region:

Desert Adapted

Water needs:

Low; Moderate

Exposure:

Filtered Sun; Shade

Mature size:

4'x4'

Growth rate:

Fast

Flower color:

Purple; Pink; White

Flower season:

Spring; Summer; Fall

Pruning:

Cold Hardiness:

18 Degrees

Nectar-producing:

Yes

Attracts pollinators:

Yes

Nighttime pollinators:

Butterflies or Moths:

Yes

Monarchs:

Yes

Larval host:

Bees:

Bats:

Birds:

Yes

Nest site:

Nest materials:

Rabbit-resistant:

Tortoises:

Yes

Growing Plants in the Desert — Important Information

The information presented here is, to the best of my knowledge, accurate and based on reliable research, personal experience in my own garden, observations from other gardens I’ve visited, and time spent studying plants in their native habitats. I always welcome your feedback and experiences to help me continue educating others!

Cacti:
In my experience, cacti are much happier in filtered shade here in the low desert of the Coachella Valley. Their colors are more vibrant and they tend to bloom more profusely, especially the non-native varieties. If you look closely at how our native barrel cactus and beavertail prickly pear grow in the wild, you’ll often find them tucked among rocks or beneath the shelter of creosote and other shrubs.

⚠️ A note of caution: Cacti and succulents are often illegally collected from the wild, which not only damages plant populations but also disturbs entire ecosystems. In some cases, wild populations of cacti have even gone extinct because of this practice. When purchasing these plants, always be sure they’ve been legally obtained. Look for nursery-grown stock or plants with a native plant certification, and keep that documentation for your records.

Light Requirements:
In our desert (Sonoran/Colorado), “full sun” doesn’t always mean what you might think. Many so-called full-sun plants benefit from and actually appreciate some late-afternoon filtered light—especially during the intense summer months.