Illustration
Purple Dome
Symphyotrichum novae-angliae 'Purple Dome'
Purple Dome blooms from September through October.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Purple Dome
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 3–8. Expect it to reach about 24 in tall and 24 in wide at maturity, in roughly 2 years (checked).
No toxicity note is on file for Purple Dome. That is not a clearance: check its safety for people and pets before planting.
What was checked
Fifteen fields were checked against named botanical sources, each recorded beside the sources that carried it, with every unsettled point written down and decided: mature height and spread, hardiness zones, sun, water, bloom months and color, the trait tags, soil, diseases, pests, toxicity, the plant's own names, and years to mature size, which rests on a recorded house rule where no publisher states one and is marked so. 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 Purple Dome
Plant Purple Dome 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 5, the middle of its hardy zones 3 to 8, spring means April to June and fall means August or September. Once settled, it blooms from September to October.
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 April. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Purple Dome get?
24 intall5 ft 7 inan adult24 inwideSee Purple Dome 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 Purple Dome
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Purple Dome about 24 in apart, center to center, so each plant has room to reach its full width.
Add Purple Dome 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
Purple Dome's height, spread, hardiness zones, sun, water, bloom months and color, years to mature size, trait tags, soil, diseases, pests and toxicity were checked against 15 published sources on August 24, 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.
- New Moon NurseryAster novae-angliae 'Purple Dome'height, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases and pests
- Missouri Botanical GardenSymphyotrichum novae-angliae 'Purple Dome'height, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil and diseases
- NC State ExtensionSymphyotrichum novae-angliaeheight, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases and pests
- RHSRoyal Horticultural Societyheight, spread, sun, water, bloom months and color, years to mature size, soil, diseases and pests
- Mt. Cuba CenterPurple Dome New England Aster, the introducerheight, hardiness zones, sun, water, bloom months and color, trait tags, soil and diseases
- Chicago Botanic GardenPlant Finderheight, hardiness zones, sun, water and bloom months and color
- gertens.comGertens (Aster, New England 'Purple Dome')height, spread, hardiness zones, sun, years to mature size and trait tags
- northwestblooms.comNorthwest Blooms (Symphyotrichum novae-angliae 'Purple Dome')height, spread, hardiness zones, sun and trait tags
- Plants For A Futurehardiness zones, bloom months and color, pests and toxicity
- thepollennation.comThe Pollen Nation (Aster novae-angliae 'Purple Dome')height, spread, hardiness zones, sun and trait tags
- University of Illinois ExtensionHort Answershardiness zones, sun, soil, diseases and pests
- NC State ExtensionSymphyotrichum, the genus entrysun, trait tags, soil and diseases
- Lady Bird Johnson Wildflower Centerbloom months and color
- Missouri Botanical GardenPlant Finderhardiness zones
- University of Wisconsin HorticultureAsterssun
How the checking works, and what each standard covers, is on the verified plants page.
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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.