Allium 'Mount Everest'
Allium 'Mount Everest' · Amaryllidaceae
Pure white globes the size of a tennis ball on tall, straight stems in late spring.
- Size
- 3½ ft tall, 10 in wide
- Zones
- 4 to 8
- Light
- Full sun
- Flowers
- Late May to mid June
- Pets
- Toxic (moderate)
- Job in a bed
- Accent
A bed built around allium 'Mount Everest'
The planner designed this bed around allium 'Mount Everest' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, full sun. It chose the other plants from the 715 that suit those conditions and its dry soil, and says below why allium 'Mount Everest' stands where it does.
The plants
- 1 Moor grass 'Greenlee' × 9, tan
- 2 October daphne × 8, pink
- 3 Wild quinine × 3, white
- 4 Brown-eyed Susan × 3, yellow
- 5 Dwarf English boxwood × 1, dark green leaves
- 6 Eastern bee balm × 3, pink
- 7 Allium 'Mount Everest' × 4, white
- 8 Greigii tulip × 3, red
Why this plant
- Nothing here is unique to it. Its leaf, flower shape and colour are all on the plan already. Its case rests on where it stands and when it performs.
Why here
- Forward of its height. At 3½ ft it is taller than eastern bee balm (20 in) behind it, but airy enough to see through.
- 4 plants in 4 places. An accent is a punctuation mark: the repeat along the bed gives it rhythm.
Why now
- In flower for four weeks. From late May to mid June.
- Part of the bed's peak. With moor grass 'Greenlee' and eastern bee balm in late May: 3 kinds at once. No week has more.
- Leaves gone by midsummer. They die back and leave bare ground. A perennial that comes up late stands beside it, and grows over the gap.
Planned as an English border: 6 of the 6 groups (100%) are drifts, longer along the bed than they are deep. October daphne and moor grass 'Greenlee' finish the front edge. Greigii tulip is the first into flower, in mid April, and October daphne the last to finish, in late October.
The planner's own design check: 13 Excellent, 4 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where allium 'Mount Everest' goes in a border
At 3½ ft it belongs at the back of a bed. In the planner's ten height classes it is moderately tall (3 to 4 ft). It is airy enough to see through, so it can also come forward and veil what is behind it.
Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
White alliums among purple ones add depth, and they glow at dusk. It has the same strong, straight stems as 'Purple Sensation', with which it mixes well.
- White globes for a cool colour scheme
- Mixing with purple alliums
- Cut flowers
What to plant with allium 'Mount Everest'
Plants recorded as good partners for it, and what each pairing does:
- Ornamental onion 'Purple Sensation': in flower together for three weeks, from late May; happy in the same dry soil.
- Salvia 'May Night': in flower together for three weeks, from late May; grows up in time to hide its dying leaves; low enough (24 in) to stand in front of it.
- Bearded iris: in flower together for four weeks, from late May; happy in the same dry soil.
Questions about allium 'Mount Everest'
Does allium 'Mount Everest' need sun or shade?
Allium 'Mount Everest' grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, of average fertility, and little watering once settled.
What zones does allium 'Mount Everest' grow in?
USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does allium 'Mount Everest' flower in my zone?
In zone 5 it flowers late May to mid June. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 4 | Late May to late June |
|---|---|
| Zone 5 | Late May to mid June |
| Zone 6 | Mid May to mid June |
| Zone 7 | Early May to early June |
| Zone 8 | Early May to early June |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should allium 'Mount Everest' be planted?
8 in (20 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 10 in (25 cm), so a group knits into one patch.
It grows 3½ ft (100 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many allium 'Mount Everest' plants do I need?
At 8 in apart, set out in staggered rows:
- 27 to fill 10 square feet (about 1 m²)
- 16 for a single row 10 ft (3 m) long
- 86 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used four in four groups.
Is allium 'Mount Everest' poisonous to dogs and cats?
Yes: moderate toxicity to people, dogs, cats and horses. Like all onions, it can damage red blood cells in dogs, cats and horses if eaten. Eating the bulbs in quantity can also upset a person's stomach.
Rated from the ASPCA. Where references disagree, the more cautious rating is used.
What can I plant to hide allium 'Mount Everest''s leaves after it flowers?
A bulb's leaves have to be left to yellow for about six weeks after flowering, to feed next year's flowers. Plant it among perennials that come up late and spread wide, and they grow over the leaves as they fade:
- Peony: 3 ft tall and 3 ft wide, in flower late May to late June.
- Blue false indigo: 4 ft tall and 4 ft wide, in flower late May to mid June.
- Daylily: 2½ ft tall and 24 in wide, in flower late June to early August.
What does allium 'Mount Everest' look like in winter?
Allium 'Mount Everest' is underground: it dies back after flowering and waits as a bulb until spring. Mark where it is, so a fork does not find it first.
More Allium
- Allium 'Ambassador' Allium 'Ambassador'
- Allium 'Gladiator' Allium 'Gladiator'
- Allium 'Globemaster' Allium 'Globemaster'
- Blue allium Allium caeruleum
- Chives Allium schoenoprasum
- Curly onion Allium senescens subsp. glaucum
- Drumstick allium Allium sphaerocephalon
- Garlic chives Allium tuberosum
- Giant allium Allium giganteum
- Golden garlic Allium moly
- Japanese onion 'Ozawa' Allium thunbergii 'Ozawa'
- Nodding onion Allium cernuum
- Ornamental onion 'Millenium' Allium 'Millenium'
- Ornamental onion 'Purple Sensation' Allium hollandicum 'Purple Sensation'
- Ornamental onion 'Summer Beauty' Allium 'Summer Beauty'
- Pink lily leek Allium oreophilum
- Schubert's allium Allium schubertii
- Sicilian honey garlic Allium siculum
- Star of Persia Allium christophii
- Turkestan onion Allium karataviense
In these guides
Every fact on record
- Type
- Bulb
- Size
- 3½ ft (100 cm) tall, 10 in (25 cm) wide
- Plant
- 8 in (20 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back, or further forward: it is airy enough to see through
- Flowers
- Late May to mid June; globes; white
- Leaves
- Medium texture, summer-dormant; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 4 to 8
- Light
- Full sun
- Soil
- Average, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Amaryllidaceae
Checked against ASPCA poison lists. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.