Illustration
Thalia
Narcissus 'Thalia'
Thalia blooms from April through April.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Thalia
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 3–8. Expect it to reach about 14 in tall and 6 in wide at maturity, in roughly 1 year (a house reading).
Is Thalia toxic to dogs or cats?
- Listed as toxic to dogs and cats by NC State Extension, Pet Poison Helpline and Royal Horticultural Society.
- Listed as poisonous to people by NC State Extension and Royal Horticultural Society.
Lists differ and none is complete. If a pet eats a plant and seems unwell, call a veterinarian or a pet poison helpline.
What was checked
Nine facts were checked against named botanical sources, each recorded beside the sources that carried it: mature height and spread, hardiness zones, sun, water, bloom months and color, the trait tags, and years to mature size, which rests on a recorded house rule where no publisher states one and is marked so. Soil, diseases, pests, toxicity and the plant's own names have not yet been read for this plant, and its trait tags are the ones a feature uses rather than every word a page prints. Each fact above carries its own mark. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Thalia
Thalia is a fall-planted bulb: get it in the ground 6 to 8 weeks before the ground freezes, typically September or October in zone 5, the middle of its hardy zones 3 to 8. It pays you back the following April.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 5, the middle of this plant's hardy range, start with zone 5 in September. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Thalia get?
14 intall5 ft 7 inan adult6 inwideSee Thalia in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
Where these facts come from
Thalia's height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 7 published sources on October 23, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- Missouri Botanical Gardenheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- whiteflowerfarm.comWhite Flower Farmheight, spread, hardiness zones, sun, bloom months and color and trait tags
- luriegarden.orgLurie Gardenheight, spread, hardiness zones, sun and bloom months and color
- adrbulbs.comA.D.R. Bulbsheight, spread, hardiness zones and bloom months and color
- Chicago Botanic Gardenheight, hardiness zones and bloom months and color
- NC State Extensionsun, water and trait tags
- RHSRoyal Horticultural Societyheight and water
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Thalia
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Safety
Every part is poisonous, the bulb most of all; the alkaloid lycorine sickens dogs, cats, horses and people. Handling the sap or bulb can cause a skin rash. per ASPCA and NC State
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.