Actual size and flowering may vary slightly based on season.
Desert Ruellia
Desert Ruellia is a rounded shrub with small glossy green leaves, pale gray stems and purple-blue flowers. It grows quickly to about 4 feet tall and 4 to 5 feet wide. The biggest bloom comes in spring, with more flowers on and off through summer and fall. It takes full sun and hot west walls on little water, and hummingbirds visit the flowers.
Best for: hot west walls, informal hedges and borders, mass plantings on slopes, and desert yards where you want color and hummingbirds on little water.
It handles west-facing walls with hot reflected sun. Full sun also keeps it dense and full of flowers, so the hottest side of the house suits it.
It grows into a rounded shrub about 4 feet tall. Plant it in a row for an informal hedge, or clip it lightly for a low border.
Set plants 2 to 3 feet apart on a bank or in a large bed. They grow quickly and fill in with purple flowers each spring.
Temperatures in the mid 20s damage the leaves and stems, and it looks thin in winter until it regrows in spring. In shade or on a north wall it flowers much less, so give it full sun.
- Plant to plant2-3 ft apart, center to center
- Mass planting2 ft apart, center to center
Water every few days at first, then stretch the time between soaks over the first two months. Water deeply and let the top of the soil dry before the next soak.
Once it is rooted, it needs little water. Extra water in the dry early summer brings more flowers. Let the soil dry between waterings.
Frost in the mid 20s can damage it, and it looks thin in winter. It recovers quickly in spring, so wait until then to cut.
After frost danger passes, trim off winter damage and shape it lightly. An occasional hard cut in early spring renews an old plant. Skip shearing into formal shapes.
Drainage test first. Dig the hole and fill it with water. If water is still sitting in the hole a day later, you likely hit caliche, clay or hard soil, so fix the drainage before planting. If it drains very fast, the soil is sandy. Standing water around roots is a common reason new plants fail.
Weed cloth. Cut it away from the planting hole and where the roots will spread. Remove any plastic sheeting completely, since it keeps water and air out of the soil.
Rock or decomposed granite with no soil underneath. Bring in soil close in texture to your native soil, mix it with the soil below, and build up enough depth for roots before planting.
If you can break through. Use a breaker bar, pick, or jackhammer. Dig through the caliche and break out the solid chunks. Backfill with the soil you dug out, with no compost or manure in the hole. Confirm drainage before planting.
If you cannot break through. Dig narrow holes through the hard layer beside the root ball, not under it, and refill them with the same soil, not gravel. If it still will not drain, plant on a low mound of the same soil.
Root ball. Check the outside edges for any roots circling around. Loosen or cut those so they grow outward. Do not break up the center of the root ball.
Depth. The top of the root ball should sit at or just slightly above the surrounding soil level. Planting too deep can lead to rot and kill the plant.
Drip emitters. At planting, put the emitters on the root ball, on different sides of the plant. After about 2 months, move them to the outer edge of the root ball. Over the first year, add emitters farther out toward the edge of the branches as roots grow. Once a plant is rooted, never water only at the trunk.
How big does Desert Ruellia get?
It grows quickly into a rounded shrub about 3 to 5 feet tall and 4 to 5 feet wide. Space plants 2 to 3 feet apart for a bed or border that fills in.
How far apart should I plant Desert Ruellia?
Plant it about 2 to 3 feet apart, center to center. Use 2 feet for a mass planting that fills in fast. The Spacing tab has the numbers.
When does it bloom?
The heaviest bloom is in spring, with more flowers on and off through summer and fall and a few in a mild winter. Give it a little extra water in the dry early summer for more flowers.
How often should I water Desert Ruellia?
Water deeply while it roots in, then let the soil dry between soaks. Once it is rooted it needs little water, but a little extra in the dry early summer brings more flowers.
Can it take reflected heat?
Yes. It takes full sun and west-facing walls with hot reflected sun. Full sun keeps it dense and flowering.
Will frost hurt Desert Ruellia?
Temperatures in the mid 20s can damage it, and it looks thin in winter, but plants handle about 20 to 25°F and recover quickly in spring. Wait until after the last frost to trim off the damage.
When and how should I prune it?
After the last frost, trim off any winter damage and shape it lightly. Skip shearing it into formal shapes.
Does Desert Ruellia spread like Mexican petunia?
No. It stays a rounded shrub and does not spread where it is not wanted. That is the main difference from Mexican petunia.
What is the difference between Desert Ruellia and purple ruellia?
Desert Ruellia is a woody shrub with small, rounded leaves that stays where you plant it. Purple ruellia, or Mexican petunia, has long narrow leaves and bigger flowers, and it spreads by seed and runners. Choose Desert Ruellia for a low-water shrub that will not spread.
Does it attract hummingbirds?
Yes. Hummingbirds visit the flowers, along with bees and butterflies. Plant it in full sun, where it flowers the most.
What soil does it need?
It needs soil that drains well, and sandy, loamy, rocky and alkaline soils are all fine. Avoid spots where water stands after irrigation.
Desert Ruellia for sale in Arizona, delivered to you
Desert Ruellia (Ruellia peninsularis), also called Baja ruellia, is a rounded shrub about 4 feet tall with glossy green leaves and purple flowers. It blooms hardest in spring and on and off into fall. Below you will find its size, spacing, water, sun, frost, pruning and wildlife, and how it differs from Mexican petunia.
Sourced from trusted Arizona growers and delivered directly to your door, job site, or property. We deliver across the Valley and to nearby towns, and quote delivery anywhere else in Arizona.
What is Desert Ruellia?
Desert Ruellia, also called Baja ruellia, is a rounded shrub with glossy green leaves, pale gray stems and purple-blue flowers. It grows quickly to about 4 feet tall, and it blooms hardest in spring and on and off into fall.
How big does Desert Ruellia get?
It reaches about 3 to 5 feet tall and 4 to 5 feet wide. It grows quickly and keeps a naturally rounded shape.
How far apart do you plant Desert Ruellia?
Plant it about 2 to 3 feet apart, center to center. Use 2 feet for a mass planting on a slope or in a large bed.
Can Desert Ruellia take a hot west wall?
Yes. It takes full sun and west-facing walls with hot reflected sun, and full sun keeps it dense and full of flowers. Shade and north walls cut down on bloom.
How often do you water Desert Ruellia in Phoenix?
Water deeply while it roots in, and let the soil dry between soaks. Once rooted it gets by on little water, and extra water in the dry early summer brings more flowers.
Will frost hurt Desert Ruellia?
Temperatures in the mid 20s damage it, and it can look thin through winter. It regrows quickly in spring, so trim off the damage after the last frost.
What is the difference between Desert Ruellia and Mexican petunia?
Desert Ruellia is a woody shrub with small leaves that stays where you plant it. Mexican petunia has long narrow leaves and spreads by seed and underground runners.
We deliver across the Valley, from Phoenix, Scottsdale and Mesa out to San Tan Valley, Maricopa and Casa Grande, and up to Prescott, Sedona, Payson and Globe. See delivery areas and rates.