Mountain spurge (Euphorbia marginata 'Kilimanjaro')
Euphorbia marginata 'Kilimanjaro' (Mountain spurge) offers stunning white-margined foliage and tolerates drought and deer with low maintenance.
Complete Plant Information
Overview
Euphorbia marginata ‘Kilimanjaro’, commonly known as Mountain spurge, is a striking annual valued for its brilliant white-margined foliage, providing a cool contrast in summer gardens. This cultivar offers the ornamental features of Euphorbia marginata but tends to grow slightly taller and bloom earlier than the species form. As an easily grown annual, Mountain spurge thrives in full sun and requires relatively little attention once established.
The visual appeal of this plant comes primarily from the showy white bracts that surround the small, inconspicuous true flowers, giving the effect of fresh snow throughout mid-summer and early fall. Euphorbia marginata ‘Kilimanjaro’ is notably low in maintenance and exhibits excellent toughness, tolerating dry conditions and rocky soils common in some landscape settings.
Gardeners appreciate the vertical accent provided by this plant, which often reaches up to three feet tall. While it is technically an annual, Mountain spurge readily self-seeds, often surprising gardeners by reappearing the following year, adding reliable, bright texture to borders and meadow plantings.
Fast Facts
- Plant Family: Euphorbiaceae
- Plant Type: Annual
- Hardiness Zones: USDA Zones 2-11
- Size at Maturity:
- Height: 1-3 ft
- Spread: 1-2 ft
- Bloom Time: July to August
- Bloom Description: Green
- Sun Exposure: Full sun
- Water Needs: Dry to medium
- Maintenance Level: Low
How to Grow
Start Euphorbia marginata ‘Kilimanjaro’ from seed, either direct-sown or started indoors 6 to 8 weeks before the final spring frost date. This plant demands sharply drained soil; it performs poorly in heavy, wet conditions, even if it tolerates dry to medium moisture once established. Planting in full sun promotes the best form, though slight afternoon shade is acceptable in extremely hot summer climates.
Once established, Mountain spurge is remarkably drought-tolerant, fitting perfectly into xeriscape designs or areas where supplemental watering is infrequent. Water sparingly, allowing the soil to dry between irrigation events, which prevents root issues common in overly moist soils. Fertilization is generally unnecessary, as this plant thrives even in poor or rocky soil mixtures.
Be aware that while Mountain spurge self-seeds readily, which can result in perennial presence in the garden, in some regions it may be considered invasive due to its successful escape from cultivation. If maintaining tight seasonal control is necessary, collect mature seeds before they drop or remove unwanted seedlings early in the spring.
Landscape Uses
The primary landscape value of Euphorbia marginata ‘Kilimanjaro’ lies in its dramatic, variegated foliage acting as a bright annual accent. Its upright structure makes it an excellent choice for filling gaps in herbaceous borders, providing necessary height without significant spread. It works well when interplanted with darker-leaved perennials or deep-colored annuals that contrast sharply with its white markings.
Consider using Mountain spurge in informal plantings, such as naturalized meadows or wildflower gardens, where its ability to self-seed is appreciated. It is also an excellent component for cutting gardens, as its long-lasting white bracts provide unexpected texture in arrangements, brightening up summer bouquets. Ensure companions share its preference for full sun and dry to medium soil conditions to maintain a cohesive planting scheme.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Euphorbia marginata, commonly called snow on the mountain, is a warm-weather annual that is native to prairies from Minnesota and the Dakotas to Colorado and Texas. The upper leaves gradually develop showy clean white margins, while the true flowers are subtended by long-lasting, petal-like white bracts that provide the main ornamental display from mid-summer into early autumn. The plant sap is a milky juice that is toxic if ingested, and handling requires care lest skin rashes occur.
Tolerances
- Rabbit
- Deer
- Drought
- Air Pollution
Potential Problems
Serious insect or disease issues are rare for Mountain spurge, contributing to its low maintenance rating. However, gardeners should be aware that aphids can occasionally become troublesome and require prompt treatment. The most significant management concern involves minimizing contact with the plant sap, which is toxic and can cause skin irritation or rashes in sensitive individuals. Always use gloves when pruning or handling Euphorbia marginata ‘Kilimanjaro’ to prevent adverse reactions.
Frequently Asked Questions
What hardiness zones is Mountain spurge suitable for?
Euphorbia marginata ‘Kilimanjaro’ is hardy in a very wide range, suitable for USDA Zones 2 through 11 when treated as an annual.
How large does Mountain spurge grow?
This plant typically reaches a mature height between 1 and 3 feet tall, with a spread of 1 to 2 feet wide.
What sun exposure does Euphorbia marginata ‘Kilimanjaro’ need?
This variety performs best when given full sun exposure, although it can handle some partial afternoon shade, especially during the hottest parts of summer.
When does Mountain spurge bloom?
The plant features its main display of white bracts from July through August, with the inconspicuous true flowers being green.
Conclusion
The textural contrast and easy cultivation make Euphorbia marginata ‘Kilimanjaro’ an invaluable annual for summer interest, especially for gardeners seeking drought tolerance and deer resistance. Integrating Mountain spurge into your planting scheme introduces lively, bright foliage that lasts until frost. Before planting, confirm your local climate fits within USDA Zones 2-11 and prepare well-draining soil to ensure a successful season for this striking annual.
Companion Planting
When selecting neighbors for Euphorbia marginata ‘Kilimanjaro’, focus on plants that share its preference for full sun and dislike consistently wet feet. Darker-leaved companions offer the best visual contrast to the white margins of Mountain spurge. Consider pairing it with deep purple foliage plants like dark-leafed Basil or contrasting textures such as dark-flowering Zinnias or Cosmos. Plants native to prairie environments, which often tolerate dry, average soils, make excellent partners for this tough annual.
Design Ideas
The upright habit of Euphorbia marginata ‘Kilimanjaro’ makes it ideal for the middle to back row of a mixed annual border to add height and brightness. Because of its low maintenance needs, it works wonderfully in sunny roadside plantings or mixed containers where other elements might struggle with dryness. For a cottage garden feel, plant drifts of Mountain spurge amongst hardy Salvias or shorter Aster varieties to weave light spots throughout the design from mid-summer onward.
