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Ornamental bulb
Amaryllidaceae
Giant white ornamental onion
‘Mount Everest’ ornamental onion (Allium stipitatum ‘Mount Everest’)
Product code : VAN-146-165-01
Allium Mount Everest is a spectacular white ornamental onion carrying a spherical 15 cm (6 in) umbel on a 90 cm (36 in) stem in late spring. The Van Noort package contains 1 Allium bulb size 18/20 for planting 15 cm (6 in) deep and 20 cm (8 in) from neighbouring bulbs. Hardy in Zones 4 to 10, white Allium stipitatum prefers sun, fertile soil, and exceptional drainage. Its starry florets attract insects, while the durable head suits white borders, contemporary gardens, and fresh or dried bouquets. Let the foliage yellow completely before cleanup so the bulb can return strongly.
- Quantity
- 2 bulbs
- Exposure
- Full sun to partial shade
- Life cycle
- Naturalizing bulbous perennial
- Hardiness
- Zones 4 to 10
Discover the plant
Common nameMount Everest ornamental onion
FamilyAmaryllidaceae
GenusAllium
Speciesstipitatum
CultivarMount Everest
TypeOrnamental bulb
Botanical nameAllium stipitatum
‘Mount Everest’ ornamental onion (Allium stipitatum ‘Mount Everest’) raises a nearly perfect white sphere approximately 15 cm (6 in) wide on a sturdy 90 cm (36 in) stem in late spring. Dozens of starry florets create a luminous white Allium flower marked by small pale green centres. Green basal strap-shaped foliage accompanies the rising stem, then begins yellowing naturally as bloom reaches its peak. Hardy in Zones 4 to 10, this bulbous perennial provides a crisp vertical accent and retains a decorative silhouette when the head dries. One large Van Noort bulb produces an impressive individual focal point.
Plant the Allium bulb size 18/20 in fall, four to six weeks before lasting soil freeze, in full sun or light partial shade. Position it point upward at a depth of 15 cm (6 in), leaving 20 cm (8 in) of space around it, in fertile, loose, exceptionally well-drained soil. Water deeply after planting, then maintain moderate moisture during spring growth without saturating the ground. A light application of compost is sufficient. Let foliage yellow completely before removal so the bulb can rebuild its reserves for the following year, and reduce irrigation substantially once summer dormancy begins.
Allium Mount Everest brightens borders, white gardens, contemporary designs, and naturalistic plantings. Install several bulbs in spaced clusters among catmint, salvias, hardy geraniums, or grasses that gradually conceal declining leaves. Its large sphere works beautifully as an Allium for bouquets, fresh or dried, and remains graphic long after flowering. Bees, bumblebees, butterflies, and other insects visit its numerous florets, while deer generally avoid the plant. It is toxic to pets, however. For container growing, choose a deep, stable, frost-resistant pot with generous drainage and keep every plant beyond the reach of curious animals.
Planting guide
Plant well.Grow beautifully.
Planting depth
15 cm (6 in)
Spacing / density
20 cm (8 in) between bulbs
Best planting time
Fall, four to six weeks before lasting soil freeze
Propagation
Bulb and offset division after dormancy
Growing method
Plant the Mount Everest bulb in fall, ideally four to six weeks before the ground freezes permanently. Select a site in full sun or very light partial shade, protected from winds that could lean the 90 cm (36 in) stem. Loosen the soil to at least 30 cm (12 in), remove compacted pockets, and incorporate a small amount of mature compost. In heavy ground, improve the entire area with a mineral drainage component or create a slight mound; a gravel layer placed only beneath the bulb may trap water instead of dispersing it. Position the size 18/20 bulb point upward at a depth of 15 cm (6 in), leaving 20 cm (8 in) to the next bulb. Cover, firm gently, and water deeply once. Mark the location, then add light mulch after the soil cools. In spring, remove compacted debris and maintain steady light moisture while the stem extends without waterlogging the soil. Feed sparingly with compost; excess nitrogen promotes soft growth. After bloom, retain the head for graphic effect or cut it for a bouquet. Never remove green leaves. Wait for complete yellowing, then reduce irrigation sharply through summer dormancy and leave the marked bulb undisturbed.
Soil and care
The right care,at the right time.
Soil pH
Acid to alkaline
Minimum temperature
-40°C (-40°F)
Care level
Easy
Drought tolerance
Yes
Watering
Water deeply after fall planting to settle soil around the bulb, then allow seasonal precipitation to take over. In spring, maintain consistent light moisture while foliage forms and the stem extends, letting the surface dry between applications. Avoid all standing water. As leaves yellow, reduce irrigation gradually and keep summer dormancy relatively dry. Container plants require closer monitoring because their mix dries faster yet must never remain saturated.
Soil type
Mount Everest thrives in fertile, loose, exceptionally well-drained loam that remains lightly moist through spring growth. A little mature compost improves structure without supplying excess nitrogen. In clay, loosen a broad area with stable organic matter and grit or plant on a mound. Avoid depressions, compacted soil, and locations receiving constant irrigation during summer dormancy. Reliable drainage matters more than an artificially precise pH range. A slight slope further improves drainage after heavy rainfall and spring snowmelt, protecting the large bulb from prolonged saturation.
Fertilization
In early spring, spread a thin layer of mature compost around emerging shoots without covering their base. In poor soil, a balanced slow-release fertilizer may be applied at half strength. Avoid nitrogen-rich feeding, which produces abundant leaves and weaker stems at the expense of flowering. Stop feeding after bloom and allow foliage to rebuild the bulb’s reserves naturally before dormancy. Container specimens benefit from similarly restrained nutrition.
Moisture
Lightly moist soil during active growth, exceptionally well drained, and drier during dormancy
Seasonal care
In spring, gently remove compacted mulch as shoots emerge and confirm that water drains after snowmelt or heavy rain. Add a thin layer of compost, then irrigate only when the surface begins drying. Protect leaves from foot traffic and install a discreet support before flowers open if the location is very windy. In late spring, observe the 15 cm (6 in) white umbel, cut several stems early in the morning for bouquets, or leave them for pollinators. Remove only damaged heads; a healthy head extends graphic interest. In summer, never cut green foliage. Wait for complete yellowing, clean at soil level, and sharply reduce watering during dormancy. Watch primarily for rot in wet sites and correct drainage instead of applying unnecessary treatments. In fall, loosen crusted surfaces without injuring the bulb, plant new specimens 20 cm (8 in) apart, and divide offsets only if a group becomes crowded. In winter, prevent traffic and water accumulation beneath ice. For a container, insulate the walls, place the pot in a sheltered location, and maintain the necessary cold without moving it into a heated room. Keep all removed plant parts beyond the reach of pets. Use a durable label to prevent accidental digging while the bulb is invisible. Inspect supports after storms, remove only broken stems, and record any poorly drained spots for correction before fall planting. Healthy dry heads may remain until they become brittle, extending the planting’s silhouette without compromising bulb reserves.
Container growing
A garden,within reach.
Recommended pot size
At least 40 cm (16 in) deep and 35 to 40 cm (14 to 16 in) wide for one bulb
Grow Mount Everest in a stable, frost-resistant container at least 40 cm (16 in) deep and 35 to 40 cm (14 to 16 in) wide for one bulb. Choose a heavy pot because the 90 cm (36 in) stem and 15 cm (6 in) sphere catch wind. Several large holes, feet beneath the container, and no standing saucer water are essential. Fill with light potting mix enriched with a little mature compost and a mineral drainage component. In fall, position the size 18/20 bulb point upward at a depth of 15 cm (6 in), then water deeply once. Place the pot in full sun or light partial shade and leave it outdoors to receive winter cold. In severe regions, temporarily sink the container, insulate its walls, or place it beside a sheltered wall; never bring it into warmth. In spring, inspect holes, water as the upper few centimetres dry, and apply a low dose of balanced fertilizer. Rotate the pot to maintain straight growth and support discreetly in a windy location. After flowering, let leaves yellow, then reduce irrigation during dormancy. Renew part of the mix every two or three years and separate offsets after complete dieback.
Bloom and dimensions
Its place,in your garden.
Mature height
90 cm (36 in)
Width / spread
Approximately 15 to 25 cm (6 to 10 in)
Flower color
Pure white with a pale green centre
Foliage color
Green
Foliage type
Deciduous, basal, and strap-shaped
Growth rate
Moderate
Growth habit
Basal rosette with a tall upright flowering stem
Fragrance
Light floral and onion fragrance
Bloom period
In late spring, Mount Everest carries a nearly spherical 15 cm (6 in) umbel composed of numerous pure white starry florets with small pale green centres. The head rises on a sturdy 90 cm (36 in) stem, remains luminous for several weeks, and attracts various insects. After petals fade, its dry structure retains useful geometry in gardens and bouquets. Grouped bulbs intensify the luminous effect and make the flowering resource easier for pollinators to locate.
Garden associations
In goodcompany.
Companion plants
Pair Mount Everest with catmint, purple salvias, hardy geraniums, pale peonies, dark heucheras, and fine grasses. These plants emphasize pure white, extend the flowering sequence, and gradually conceal yellowing leaves. Late tulips establish a harmonious spring transition. Preserve air around stems, however, and avoid thirsty neighbours that keep the soil wet through summer dormancy. Silver foliage creates an especially effective luminous background for the large white globes. Restrained groundcovers can fill spaces without competing with the bulbs, provided the crown remains airy and their watering needs stay moderate through summer dormancy.
Frequently asked questions
Your questions,answered.
When and how should Allium Mount Everest be planted?
Plant the bulb in fall, four to six weeks before lasting soil freeze. Choose full sun or light partial shade in fertile, loose, exceptionally well-drained soil. Position the size 18/20 bulb point upward at a depth of 15 cm (6 in) and leave 20 cm (8 in) to the next bulb. Cover, firm gently, and water deeply once. In clay, improve a broad area with mature compost and grit or create a slight mound. Mark the location so it remains undisturbed during dormancy. In spring, maintain moderate moisture during active growth, then reduce irrigation as foliage yellows. Avoid standing water in every season.
How large does the Mount Everest flower become?
The stem reaches approximately 90 cm (36 in) and carries a spherical umbel about 15 cm (6 in) in diameter. The head consists of numerous pure white starry florets with small pale green centres rather than one massive flower. Its scale rises above low perennials while remaining easy to integrate into a residential border. To strengthen the effect, plant several bulbs in odd groups spaced 20 cm (8 in) apart. Bright exposure and drained soil encourage sturdy stems. In a windy location, install discreet support before opening so a fully loaded stem is not bent. The globe may remain decorative after petals fade.
Does Mount Everest return every year in Canadian gardens?
Yes. This perennial bulb can return in Zones 4 to 10 when drainage is dependable. In cold Canadian regions, plant early enough in fall for roots to form before lasting freeze without encouraging extended top growth. After flowering, let every leaf yellow and dry completely because foliage rebuilds reserves required for the next cycle. Then reduce irrigation during summer dormancy and avoid wet depressions. Failure to return is often linked to rot, foliage removed too early, or a disturbed bulb. Mark the location and divide offsets only when a group becomes crowded. Replant divisions promptly at the original depth. Immediately.
Can Mount Everest be cut for bouquets?
Yes. For a fresh bouquet, cut the stem early in the morning when several florets are open but the umbel remains firm. Use a clean tool, place the stem immediately in water, and choose a stable vase suited to a 90 cm (36 in) length. One white sphere can serve as a focal point; three stems create an architectural effect. For drying, harvest a mature head that is still solid, remove leaves, and hang it upside down in a dark, dry, ventilated location. The structure retains its geometry for a long time. Leave several heads in the garden for insects and visual interest, then handle dry parts away from pets.
Can Mount Everest grow in a container?
Yes. Use a heavy, frost-resistant pot at least 40 cm (16 in) deep and 35 to 40 cm (14 to 16 in) wide with several large holes. Fill it with light potting mix enriched with compost and mineral drainage material. Plant the bulb 15 cm (6 in) deep, water once, and leave the container outdoors in sun to receive winter cold. In severe regions, insulate the walls or temporarily sink the pot without bringing it into warmth. In spring, rotate it to balance the stem, water as the surface dries, and support it in a windy site. After foliage yellows, reduce irrigation sharply through dormancy.
Wildlife and pets
Life,around your plants.
Reported toxicity
Yes
Supporting wildlife
Mount Everest’s numerous florets provide pollen and nectar for bees, bumblebees, butterflies, and other insects in late spring. Plant several bulbs in groups to make this resource easier to locate and avoid insecticides during bloom. Birds and hummingbirds are not its principal visitors. The plant is generally deer resistant once established in a suitable site.