Gladiolus 'Mount Everest' (L)

RHS Plant Profile
sword lily 'Mount Everest'

Save a plant

Where do you want to save Gladiolus 'Mount Everest' (L)?

Plants I own
Wishlist
Go to My Plants
sword lily 'Mount Everest' RHS / Joanna Kossak
Bulbs

A giant-flowered gladiolus, 1.2m high, with green leaves and spikes of white flowers, eight to ten open at one time, from midsummer to late summer

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

1-1.5 metres

Max Spread

0-0.1 metre

Size

Time to Maturity
2–5 years
Max Spread
0-0.1 metre
Max Height
1-1.5 metres

Growing Conditions

Chalk Loam Sand
Moisture
Moist but well–drained or Well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun
Aspect
West–facing or South–facing
Exposure
Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

  • H1A: under glass all year (>15C)
  • H1B: can be grown outside in the summer (10 - 15)
  • H1C: can be grown outside in the summer (5 - 10)
  • H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
  • H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
  • H4: hardy through most of the UK (-10 to -5)
  • H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
  • H6: hardy in all of UK and northern Europe (-20 to -15)
  • H7: hardy in the severest European continental climates (< -20)
H3

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Iridaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Columnar upright
Potentially harmful
Ornamental bulbsnot to be eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus
Gladiolus are cormous perennials with fans of sword-shaped or linear leaves and spikes of funnel-shaped flowers
Name Status
Accepted
Horticultural Group

Horticultural Classification Codes

Horticultural Classification Codes are often given to genera which have a large number of species or cultivars. They are used to categorise cultivated plants based on specific, shared characteristics such as shape, colour, size or flowering time, and can be displayed as letters or numbers

For example:
Dahlia ‘Sunset Kate (Sin) = Single flower
Rosa ‘Marigold’ (HT) = Hybrid Tea

Large-flowered Grandiflorus Group gladioli have flowers 11-14cm across in summer

How to Grow

Cultivation

Grow in fertile, well-drained soil in full sun, planting the corms 15cm deep in spring, on a bed of sharp sand to aid drainage; in frost-prone areas, lift when the leaves turn yellow-brown, and store the new corms in a dry, frost-free place until the following spring; in milder areas, add a thick dry mulch over winter This plant was included in the RHS Gladiolus (gladioli) trial 2024-2025 https://www.rhs.org.uk/plants/trials-awards/ongoing-plant-trials/gladiolus

Propagation

Propagate by division, separating cormlets when dormant

Suggested planting locations and garden types

  • City and courtyard gardens
  • Cottage and informal garden
  • Cut flowers
  • Flower borders and beds
  • Wall side borders

Pruning

No pruning required

Pests

May be susceptible to gladiolus thrip, aphids and slugs

Diseases

May be susceptible to gladiolus corm rot, grey moulds (Botrytis), Fusarium bulb rot, gladiolus core rot, gladiolus dry rot, gladiolus scab and neck rot, fungal leaf spot, and virus diseases