Illustration
Clara Curtis
Chrysanthemum 'Clara Curtis'
Clara Curtis blooms from August through October.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Clara Curtis
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 3–9. Expect it to reach about 2.5 ft tall and 2 ft wide at maturity, in roughly 2 years (a house reading).
Is Clara Curtis toxic to dogs or cats?
- Listed as toxic to dogs by NC State Extension and Pet Poison Helpline.
- Listed as toxic to cats by NC State Extension.
- Listed as poisonous to people by NC State Extension.
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 Clara Curtis
Plant Clara Curtis in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 6, the middle of its hardy zones 3 to 9, spring means March to May and fall means August or September. Once settled, it blooms from August to October.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 6, the middle of this plant's hardy range, start with zone 6 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Clara Curtis get?
2.5 fttall5 ft 7 inan adult2 ftwideSee Clara Curtis in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Clara Curtis
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Clara Curtis about 2 ft apart, center to center, so each plant has room to reach its full width.
Add Clara Curtis to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Clara Curtis' height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 7 published sources on October 21, 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.
- Perennials.com (Heritage Perennials)Heritage Perennials (Valleybrook)height, spread, hardiness zones, bloom months and color and trait tags
- RHSRoyal Horticultural Societyheight, sun, water and bloom months and color
- whiteflowerfarm.comWhite Flower Farmheight, spread, hardiness zones and bloom months and color
- Chicago Botanic Gardenhardiness zones, sun and bloom months and color
- horsfordnursery.comHorsford Gardens and Nurseryheight, spread, hardiness zones and trait tags
- redbuttegarden.orgRed Butte Garden (University of Utah)height, spread, hardiness zones and water
- NC State Extensionsun
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Clara Curtis
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Safety
Toxic to dogs, cats and horses, and a skin irritant to people. Eating it usually causes mild stomach upset, drooling and diarrhea; NC State rates it low-severity. 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.