The illustrated growing guide

Gladiolus

Gladiolus × hortulanus

Family Iridaceae

Est. zones 8-10

Botanical illustration of Gladiolus — Bulb · Gladiolus × hortulanus

Funeral-flower reputation, farm-stand heart — a $6 bag of corms is 8 weeks of armload bouquets. Succession planting is the whole trick.

Bulb

Where to buy the plant — 1 nursery

Overview

Will gladiolus suit your garden, and what goes wrong.

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Will it fruit where you are?

Enter your ZIP — we look up your USDA hardiness zone (2023 map) and check it against what gladiolus actually needs.

Life cyclePerennial zones 8–10, annual elsewhere

Gladiolus at a glance

Life cyclePerennial zones 8–10, annual elsewhere

Mature size2-5 ft spikes

PollinationHummingbirds visit

Chill requirementNot yet established

Bloom seasonJuly - September — plant corms every 2 weeks May-June for a relay

Harvest seasonCut spikes when the LOWEST bud shows color — the rest open in the vase

Growth rateFast (bloom 70-90 days after planting)

Common gladiolus problems

THRIPS (silvered streaky blooms — the glad plague)
Aphids
Corm Rot
Fusarium

Growing

Light, water, soil, propagation and the season’s jobs.

How to grow gladiolus: light, water & soil

LightFull Sun

WaterModerate

SoilWell-drained, average · pH 6.0 - 6.5

FertilizerFeed at 6 leaves and at spike show

PruningFrost → dig corms, cure 3 weeks, store dry at 40-50°F (or rebuy — they're cheap) — Stake rows with a string corridor; cut spent spikes but keep 4 leaves to recharge the corm.

Spacing6 in apart, 4-6 in deep

How to plant & propagate gladiolus

PropagateOffsets, division, or bulbils

When to spray gladiolus

Dormant season. Dust stored corms if thrips rode along.

Growing season. Release-friendly: blast or soap thrips early; badly streaked spikes get cut and binned.

Timing only — the label is the law

This is when to watch and when a treatment is worth considering, not a recommendation to apply any product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.

Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
Confirm the product is registered for gladiolus in your state. A product legal on one crop is not legal on all of them, and state registrations differ — your state pesticide agency or local extension office can confirm both.
Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.

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The year

What gladiolus asks for, month by month.

The gladiolus year, month by month

MonthJanFebMarAprMayJunJulAugSepOctNovDec

Bloom

What each band means

Bloom — flowers open — pollinators working, frost on blossoms is the danger.

The gladiolus year as text

Jan quiet month
Feb quiet month
Mar quiet month
Apr quiet month
May bloom
Jun bloom
Jul bloom
Aug bloom
Sep bloom
Oct quiet month
Nov quiet month
Dec quiet month

These are the species' typical months — expect them a few weeks earlier in warm zones and later in cold ones. Watch the plant, not just the calendar.

Ecology & uses

What it does for the garden, and what it is grown for.

Gladiolus in the garden system

AttractsHummingbirds

MoistureFacultative / average

DeerBrowsed — protect young plants

OriginIntroduced

What gladiolus is grown for

! Some parts toxic — see notesToxic to pets (corms worst)

UseBucket bouquets

UseFarm stands

UseKids' cutting rows

Harvesting & storing gladiolus

Cut spikes when the LOWEST bud shows color — the rest open in the vase.

Edibility, identification, and traditional-use notes here are general reference — not medical or veterinary advice, and not a claim that any plant treats or prevents anything. Medicinal ratings record how strongly a plant features in herbal tradition, nothing more. Never eat or dose a plant you have not positively identified. More on how to use this library.

Cultivars

Named varieties of gladiolus, ruled as a catalogue.

Best gladiolus varieties & cultivars

'Priscilla' (ruffled bicolor); Grandiflora mixes; 'Atom' (small, elegant); hardy G. nanus (z5!)

Sources & plant ID

Where the care distinctions come from, and how the plant is filed.

Research basis

Sources behind this profile

No extension citations are attached to gladiolusyet. The care figures below come from the library's own catalogue rather than a traced primary source.

Plant ID

BinomialGladiolus × hortulanus

FamilyIridaceae

TypeBulb · Tender Perennial

USDA symbolGLGA2

OriginIntroduced

Invasive riskLow

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Where to buy

Third-party nurseries — not Story Thyme Farms.

Third-party nurseries, not Story Thyme Farms. Prices are theirs.

Story Thyme Farms may earn a small commission from these links, at no cost to you — it never changes what we recommend.

EtsyBrowse growers↗

VIII

Questions

Gladiolus questions, answered straight.

Is gladiolus safe for kids and pets?

With care. Toxic to pets (corms worst) Site it accordingly if children or pets roam the garden. This is general reference, not medical or veterinary advice — call a vet or poison control if something has actually been eaten.

When do you harvest gladiolus?

Cut spikes when the LOWEST bud shows color — the rest open in the vase.

How do you propagate gladiolus?

Offsets, division, or bulbils.

Elsewhere

Where gladiolus sits in the library.

Grows in the same world