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Allium 'Gladiator'

Allium 'Gladiator' · Amaryllidaceae

Allium 'Gladiator' (Allium 'Gladiator') in flower
Photo: Agnieszka Kwiecień, Nova, via Wikimedia Commons (CC BY-SA 4.0)

Dense, rose-purple globes as wide as a hand on stems as tall as a person's chest, in early summer.

Size
4 ft tall, 10 in wide
Zones
4 to 8
Light
Full sun
Flowers
Late May to late June
Pets
Toxic (moderate)
Job in a bed
Accent

A bed built around allium 'Gladiator'

The planner designed this bed around allium 'Gladiator' 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 'Gladiator' stands where it does.

A 12 × 6 ft (3.7 × 1.8 m) bed at eye level in mid June: Moor grass 'Greenlee', October daphne, Wild quinine, Brown-eyed Susan, Dwarf English boxwood, Eastern bee balm, Allium 'Gladiator', Greigii tulip.
A 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, full sun, seen from the path in mid June.
4. Brown-eyed Susan44. Brown-eyed Susan44. Brown-eyed Susan43. Wild quinine33. Wild quinine33. Wild quinine35. Dwarf English boxwood52. October daphne22. October daphne22. October daphne22. October daphne22. October daphne21. Moor grass 'Greenlee'11. Moor grass 'Greenlee'11. Moor grass 'Greenlee'11. Moor grass 'Greenlee'16. Eastern bee balm66. Eastern bee balm66. Eastern bee balm62. October daphne22. October daphne22. October daphne21. Moor grass 'Greenlee'11. Moor grass 'Greenlee'11. Moor grass 'Greenlee'11. Moor grass 'Greenlee'11. Moor grass 'Greenlee'18. Greigii tulip8. Greigii tulip8. Greigii tulip8. Greigii tulip8. Greigii tulip8. Greigii tulip8. Greigii tulip7. Allium 'Gladiator'7
From above, to scale. Each circle is one plant, as wide as the room it needs.

The plants

  1. 1 Moor grass 'Greenlee' × 9, tan
  2. 2 October daphne × 8, pink
  3. 3 Wild quinine × 3, white
  4. 4 Brown-eyed Susan × 3, yellow
  5. 5 Dwarf English boxwood × 1, dark green leaves
  6. 6 Eastern bee balm × 3, pink
  7. 8 Greigii tulip × 7, red

Why this plant

  • The only purple.

Why here

  • Forward of its place. At 4 ft it belongs at the back of the bed: this far forward it stands in the way of what is behind it.
  • One plant. An accent is used singly, like a punctuation mark.

Why now

  • In flower for four weeks. From late May to late 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. Cool colours (pink and purple) with yellow and red as the warm notes, and tan and white to calm things between them. The bed is balanced: the left half carries 48% of the visual weight and the right half 52%.

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 'Gladiator' goes in a border

At 4 ft it belongs at the back of a bed. In the planner's ten height classes it is moderately tall (3 to 4 ft).

Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.

Taller than 'Purple Sensation' and a little later, so the two together keep the globes going for five weeks. A sterile hybrid, so it does not seed about.

  • Tall purple globes in early summer
  • Dotting through perennials
  • Cutting and drying

What to plant with allium 'Gladiator'

Plants recorded as good partners for it, and what each pairing does:

  • Catmint 'Six Hills Giant': in flower together for four weeks, from late May; grows up in time to hide its dying leaves; happy in the same dry soil.
  • Peony: in flower together for four weeks, from late May; grows up in time to hide its dying leaves.
  • Bearded iris: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for three weeks; happy in the same dry soil.

Questions about allium 'Gladiator'

Does allium 'Gladiator' need sun or shade?

Allium 'Gladiator' 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 'Gladiator' 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 'Gladiator' flower in my zone?

In zone 5 it flowers late May to late June. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.

Roughly when allium 'Gladiator' is in flower
Zone 4Early June to late June
Zone 5Late May to late June
Zone 6Late May to late June
Zone 7Mid May to mid June
Zone 8Early May to mid 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 'Gladiator' be planted?

10 in (25 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.

It grows 4 ft (120 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many allium 'Gladiator' plants do I need?

At 10 in apart, set out in staggered rows:

  • 17 to fill 10 square feet (about 1 m²)
  • 13 for a single row 10 ft (3 m) long
  • 55 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 one in one group.

Is allium 'Gladiator' 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.

What can I plant to hide allium 'Gladiator''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, a recorded partner, in flower late May to late June.
  • Catmint 'Six Hills Giant': 3 ft tall and 3 ft wide, a recorded partner, in flower late May to early September.
  • Blue false indigo: 4 ft tall and 4 ft wide, in flower late May to mid June.

What does allium 'Gladiator' look like in winter?

Allium 'Gladiator' 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

In these guides

Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8

In flower in: May · June

Every fact on record

Type
Bulb
Size
4 ft (120 cm) tall, 10 in (25 cm) wide
Plant
10 in (25 cm) apart
Height class
Moderately tall (3 to 4 ft)
Place in the bed
Back
Flowers
Late May to late June; globes; purple, lavender
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

Not yet checked against an outside reference: its figures rest on general horticultural knowledge. 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.