Lady slipper is a unique upright plant with charming orange slipper-shaped flowers. It’s a chameleon that takes on different colors and forms depending on its microclimate. Here’s everything you need to know about planting and caring for this low-maintenance Sonoran Desert native.
Lady slipper (Euphorbia lomelii) is one of the most attractive and unique succulents you can grow in your southwest garden. It has rigidly upright stems — that sometimes twist and bend into interesting curly ques.
Its green stems are photosynthetic, while its leaves are so small you might not notice them. Its stems can range from gray-green to nearly red and are covered with a waxy finish that makes them appear frosted.
Its brilliant red-orange flowers aren’t large but they are charmingly shaped like slippers or Barbie doll shoes. Flowers are followed by small pods that look like paper lanterns.
Each clump’s microenvironment dictates its size, color, and growth habit, so that no two lady slippers look exactly alike. I have several, and they all have their own personality!
Lady slipper is an extremely low-maintenance plant. Once established, it needs minimal irrigation. It requires almost no pruning and produces no obvious litter.
Lady slipper flowers are a magnet for hummingbirds but not for insects, which can’t reach the nectar due to the flower’s unusual shape.
Why I Like This Plant
- Attractive plant adds architectural interest all year long
- Charming coral red slipper-shaped flowers
- Low maintenance, needs little water, litter-free
- Hummingbird magnet
- Every plant has a unique form and coloration
Things to Watch Out For
Like all members of the Euphorbia genus, lady slipper exudes milky sap that is toxic to ingest and can be irritating to the skin.
Warning! ⚠️
According to the ASPCA website,
lady slipper is listed as not toxic to dogs.
This is incorrect.
There is more than one plant called lady slipper.
The ASPCA refers to a different species.
Optimal Growing Conditions
If you’re thinking of adding a lady slipper plant to your garden, you need to find a suitable place that will keep your plant healthy and looking good… while minimizing maintenance for you.
Here are the key factors to keep in mind.
Temperature
Lady slipper should be grown in USDA Hardiness Zones 9 – 11. Plants get more cold tolerant as they mature. Young stems can be damaged below 30℉ while mature stems are cold-hardy down to 25℉ and can withstand brief cold spells down to 20℉.
I generally start mine in pots that can be moved to a sheltered patio during cold snaps, then plant them in the ground after a few years.
Sun Exposure
Lady slipper can exist in all light conditions — from full sun and reflected heat to light shade. I have some on the north side of my house that get full sun in the summer and full shade in the winter, and they look beautiful all year.
In very hot microclimates, they appreciate some filtered shade, especially in the afternoon.
Lady slipper responds in some cool ways to good stress. They turn more red in full sun or when they experience extreme sun or cold. They grow more erect in the sun and get more curly in the shade.
Size and Growth Rate
Lady slipper is a moderately fast grower. After a few years, they start sending up new stems to grow wider. Clumps are usually 3 feet tall and wide, but I’ve seen them much taller — up to 5 or 6 feet.
Soil
Lady slipper is not particular about soil and grows in any native desert soil, as long as it’s well-draining.
If you grow one in a container, be sure it has good drainage and use specifically formulated cactus soil. Once in pots, they don’t mind being crowded.
If you plant new lady slippers in a pot, they tend to fall over. You can temporarily tie them together loosely or prop them up with rocks or gravel until they can stand on their own.
Other Location Considerations
Since lady slipper is tall, narrow, and litter-free, it’s a good plant for narrow spaces like along sidewalks or pools. But since it is toxic and can be irritating to touch, keep it where kids and dogs won’t get at it.
Lady Slipper:
The Essentials
| Common Names | Lady slipper, lady’s slippers |
| Scientific Name | Euphorbia lomelii |
| Origin | Sonora, Baja California, Mexico |
| Plant Type | Succulent |
| USDA Zones | Zones 9 – 11 |
| Cold Hardiness | To 25℉ |
| Flower Color | Red-orange |
| Flower Season | Spring, summer |
| Mature Size | 3-5′ high x 3-5’ wide |
| Growth Rate | Moderate |
| Sun Tolerance | Full, part, reflected sun |
| Water Needs | Low |
| Pests & Diseases | Root rot if overwatered |
| Toxicity | Toxic to people, pets, livestock |
| Wildlife | Attracts hummingbirds Deer, rabbit, javelina resistant |
How to Plant
Dig a hole as deep as and twice as wide as the nursery container. Carefully remove the plant from the container, put it in the hole, and press the soil to remove any air pockets.
It’s generally recommended that you backfill with only native soil and not add any amendments. However, good drainage is critical. So if you know your soil is slow draining, amend with coarse sand or small gravel until you have a loose, well-drained mix.
Since lady slipper exudes toxic sap, handle with care. When dealing with plants like lady slipper, I put a pair of inexpensive disposable gloves over my regular gardening gloves and then toss them when done. If you get sap on your gardening tools, clean them thoroughly before putting them away.
When to Plant
The best time to plant succulents is April or May when warm soil temperatures encourage root development.
How to Care for Lady Slipper
Whether you’ve recently planted a lady slipper or have an existing plant in your yard, here’s how to take care of it to keep it healthy and looking its best.
How to Water
You’re probably used to giving a plant a good soaking immediately after transplanting, but that isn’t the best practice with succulents like lady slipper.
The Arizona-Sonora Desert Museum advises not to water succulents for one to two weeks after planting. Then water every 2 weeks spring through fall, and every 3 to 4 weeks during the winter.
Since firesticks have shallow roots, there is no need to water deeply. Watering to a depth of one foot is sufficient.
If you’re growing lady slipper in a container, use this watering schedule as a guide.
| Spring & Fall | Every 7-10 days |
| Summer | Every 5-7 days |
| Winter | Every 10-14 days |
Should You Fertilize?
There is no need to fertilize lady slipper if planted in the ground, they get all the nutrients they need from the surrounding desert soil. Fertilizing can result in fewer flower blooms.
But if you keep it in a pot, fertilize lightly a few times a year when it’s actively growing.
Pruning and Propagation
This plant rarely needs pruning except to remove dead or damaged stems which can be done anytime of the year.
When stems die, they eventually turn into bleached-out sticks. At this point, you can easily snap them off at the base with your hands — they no longer contain any sap.
If you trim back any live stems, you can use them to grow new plants. Simply let the cut ends dry in the shade for a week or so, then stick them into cactus soil and water infrequently.
Lady Slipper Cultivars
If you live where cold limits your ability to grow lady slipper, consider the Chilly Willy lady slipper cultivar.
Pedilanthus macrocarpus ‘Chilly Willy’ is a cold-hardy selection from Tucson’s Civano Growers. Their trials have found that Chilly Willy can survive a full week of temperatures below 32°F and temperature dips as low as 12°F with no damage.
Don’t Confuse Lady Slipper With…
Lady slipper is sometimes confused with these other succulents.
Candelilla (Euphorbia antisyphilitica) is another upright succulent that looks like a miniature version of lady slipper. Its stems are half as thick (1/5 inch vs nearly 1/2 inch), it’s not as tall (1-2 ft vs 3-5 ft), and it has tiny pink flowers in the spring.
Firesticks (Euphorbia tirucalli) is another upright succulent, but it has branching, brightly colored stems and looks more like coral than a plant that belongs in the desert.
There is another plant (Euphorbia bracteata) that goes by the name slipper plant or appropriately “tall slipper plant” since it gets 8 feet tall and 6 feet wide. It is a close botanical relative to lady slipper but has obvious leaves and clusters of red-orange bracts.
And finally, there are plants you won’t find in the desert called lady slipper, such as lady slipper orchid and a lady’s slipper that’s a member of the impatiens genus.
Plant Lover Facts
Lady slipper has several common names and a few scientific ones.
Most common names are variations of the footwear theme — Lady’s slippers, slipper plant, slipper flower, and the Spanish zapato del diablo (“devil’s shoe”).
The genus name Pedilanthus is a composite of the Greek words pedilon (shoe) and anthos (flower).
When research analyzed the milky white sap of lady slipper, it was found to be 6% to 10% rubber.
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Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for 15 years.
Our lady slippers plants are getting too tall for us…can they be trimmed back?
If they’re getting that big, they must be happy! You don’t want to cut them back like a shrub. If only some of the branches are getting too tall, you can selectively cut the tallest ones down to the ground. If the whole plant is too tall, you could dig it up, take cuttings and start over.
Thank you for your help! I guess we’ll have to start over!
We just moved to Chandler, AZ in February. Late in April, we had our back yard landscaped. One of the plants I chose is a lady slipper. They are so enchanting. Although according to you we are over watering ours, it is thriving and has already started pushing up new shoots at the base. It’s so satisfying to watch its rapid growth.
Enchanting is the perfect word for describing lady slipper! It’s one of my favorites. It sounds like yours is happy, so I wouldn’t change a thing.