Gladiolus Gladiolus x hortulanus
Gladiolus (Gladiolus x hortulanus) is a deciduous perennial flowering plant in the Iridaceae family, native to Garden hybrids of South African and Mediterranean species; raised in Europe. It grows 90 cm–1.5 m (35 in–4.9 ft) tall and 15–30 cm (6–12 in) wide, wants full sun and moderate water, and is hardy to about -9 °C (16 °F). Space plants about 15 cm (6 in) apart.
Plan Gladiolus in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Gladiolus at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Iridaceae |
| Mature height | 90 cm–1.5 m (35 in–4.9 ft) |
| Mature spread | 15–30 cm (6–12 in) |
| Spacing | 15 cm (6 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance none |
| Soil pH | 6–7 |
| Cold hardiness | About -9 °C (16 °F) once established (roughly USDA zone 8) |
| Heat stress | Likely above about 32 °C (90 °F) |
| Flowering | from about July for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | None |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Native to | Garden hybrids of South African and Mediterranean species; raised in Europe |
| Common in gardens of | 🇿🇦 South Africa, 🇺🇸 United States, 🇷🇺 Russia |
Is Gladiolus toxic?
- People: mildly toxic
- Cats: mildly toxic
- Dogs: mildly toxic
- Parts: corms, bulbs
Corms contain saponins that can cause drooling, vomiting and diarrhoea.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Gladiolus
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
Questions about Gladiolus
- How far apart should I plant Gladiolus?
- About 15 cm (6 in) apart, centre to centre. A mature plant spreads 15–30 cm (6–12 in).
- Does Gladiolus need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Gladiolus need?
- Moderate water. Drought tolerance is low and waterlogging tolerance none.
- How cold-hardy is Gladiolus?
- It tolerates about -9 °C (16 °F) once established, roughly USDA zone 8.
- When does Gladiolus flower?
- From about July for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Gladiolus poisonous to cats and dogs?
- For cats it is mildly toxic; for dogs mildly toxic; for people mildly toxic. Corms contain saponins that can cause drooling, vomiting and diarrhoea.
- What grows well with Gladiolus?
- There is no well-documented companion pairing for Gladiolus. Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade C (C: plausible, mixed evidence).
- RHS Plant Finder, Royal Horticultural Society
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
Notes and assumptions
- Typical garden-form values; cultivars and local conditions differ.
- Corms are normally lifted and stored indoors in winter where winter lows fall below about -7 C.
- Stake tall spikes; thrips and fusarium are common problems.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Bearded iris Iris germanica
- Japanese iris Iris ensata
- Siberian iris Iris sibirica
- Dutch crocus Crocus vernus
- Freesia Freesia refracta hybrids
- Montbretia (crocosmia) Crocosmia x crocosmiiflora
- African iris Dietes grandiflora
- Bugle lily (watsonia) Watsonia borbonica