Euphorbia marginata [yoo-FOR-bee-uh, mar-gin-AY-tuh] is a member of the family Euphorbiaceae and also known as:
- White Margined Spurge
- Snow on the Mountain
- Smoke on the Prairie
- Variegated Spurge
The Euphorbia plant’s genus name is thought to be in honor of Euphorbius, who was the physician of the king of Mauritania.
The specific epithet, marginata, refers to the white margins of the leaves.
This warmth-loving, annual plant is native to many of the warmer parts of North America.
It is found growing wild in areas ranging from the southwestern United States through eastern Canada.
As it has grown in popularity as a cultivated plant, it has also become naturalized in many parts of China.
These wildflowers require very little care.
Although they are annual plants, they reseed freely and return to your garden year-after-year.
For this reason, even though the plant is not winter hardy, it does grow happily in USDA hardiness zones 2 through 11.
Euphorbia Marginata Care
Size & Growth
Snow on the mountain can grow to be about 3′ feet high.
It is a single-stemmed, non-branching plant.
Variegated spurge leaves are about 3″ inches long.
They are medium green in color in the springtime and gradually develop clean, attractive white margins as the growing season progresses.
Flowering & Fragrance
The actual flowers are rather unremarkable. They are small and greenish-yellow.
They appear at the ends of the stems in the middle of the summer and remain until early in the autumn.
The surrounding rounded white bracts are flowerlike in appearance and are quite attractive.
Light & Temperature
Provide full sunlight and warm temperatures. If you live in an area of extreme heat with punishing sunlight, afternoon shade will be appreciated.
While the plant will grow in partial shade, it tends to have a flaccid shape without ample sunlight.
Additionally, blooms are sparse in a light shade setting.
Watering & Feeding
Although White Margined Spurge is a succulent plant, it is not drought resistant.
If you live in a very hot, dry area, you should water deeply once a week.
Check frequently, and if you find the top several inches of soil is dry, it’s time to water.
Because these plants are wildflowers, they have little need for fertilizer.
If your soil is exceptionally poor or you are keeping Smoke on the Prairie as a container plant, you may need to provide a light feeding of diluted (half strength) fertilizer once a month.
Soil & Transplanting
As with most spurge, these plants appreciate well-draining soil of almost any pH. They can tolerate very poor soil, even sandy, and rocky soil.
Mature plants should be spaced 6″ – 9″ inches apart.
Grooming & Maintenance
These easy-care plants require little in the way of grooming and maintenance.
Trim away dead or straggly limbs as they occur, and shape the plant as you wish.
Cut back before the small blossoms go to seed if you do not want the plant to spread.
Cut back later in the autumn for a tidier appearance during the winter months.
How To Propagate Snow on the Mountain
Even though these Euphorbia do reseed themselves easily, growing from seed is not always the best way to go when you start out.
Instead, you may want to begin with plant cuttings.
Take care to protect yourself from the milky white sap, which is irritating to your skin.
If you do decide to grow Euphorbia marginata from seed, start the seeds indoors a couple of months before your last expected frost date.
Alternately, you may be able to sow them directly into the soil outdoors early in the springtime.
Seeds need a consistent temperature of 60° degrees Fahrenheit (15° C) to germinate.
You should see new growth within a couple of weeks.
Follow seed packaging instructions for your hardiness zone.
Choose strong, healthy stems as cuttings.
Remove lower leaves and dip the stems in rooting powder before placing them into a light, airy, well-draining rooting medium.
Water them in and place the container in a consistently warm area where the cuttings can receive bright, indirect sunlight.
After a couple of weeks, the cutting should produce good roots and begin to grow new vegetation.
When this happens, transfer them to their permanent container or outdoor setting.
Add a little organic matter to the planting hole to provide the young plants with extra nourishment for a good start.
Snow on the Mountain Main Pest or Disease Problems
These plants may be subject to root rot if they are left to stand in water.
It is very important to provide loose, airy, light, well-draining soil to avoid problems with fungal infection.
As with most spurge, pests are unusual; however, spider mites and mealybugs may be a problem if plants are overcrowded or overwatered.
Overcrowding and overwatering will cause trouble with powdery mildew.
Overall, choosing an appropriate planting setting, providing ample sunlight and air circulation, and watering the right amount will produce trouble-free Euphorbia marginata.
Learn more about Succulent Pest
Is The Snow on the Mountain Plant Toxic or Poisonous?
As with all spurges, you must be careful of the white sap.
It is a skin irritant, and if ingested, it is toxic.
Wear gloves and eye protection and long sleeves when handling and working with this plant.
Keep it out of the reach of children and pets.
Is The Marginata Euphorbia Invasive?
Even though this is a native plant, it is also considered an invasive plant in some areas.
In parts of the United States where it does not naturally belong, it nonetheless makes itself right at home and is considered a pest.
As mentioned, it has also naturalized happily in China.
Suggested Euphorbia Marginata Uses
These rugged wildflowers are an ideal choice as a border plant, in a cutting garden or naturalized in a meadow.
They are resistant to air pollution, as well as predation by deer and rabbits.