Wood's Blue (Symphyotrichum dumosum 'Wood's Blue') - blue flowers, illustrated plant cardIllustration

Wood's Blue

Symphyotrichum dumosum 'Wood's Blue'

Wood's Blue blooms from September through October.

Bloom calendar
Bloom time
Sep–Oct
checked
Hardiness
Zones 4–8
checked
Sun
Full sun
checked
Water
Moderate water
checked
Mature size
16 in × 16 in
checked
Type
Perennial
house classification

Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.

Growing Wood's Blue

Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 4–8. Expect it to reach about 16 in tall and 16 in wide at maturity, in roughly 2 years (checked).

No toxicity note is on file for Wood's Blue. That is not a clearance: check its safety for people and pets before planting.

Verification
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.

See the 9 sources it was checked against

When to plant Wood's Blue

Plant Wood's Blue 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 4 to 8, spring means March to May 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 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 Wood's Blue get?

Illustration of Wood's Blue drawn to scale beside an adult16 intall5 ft 7 inan adult16 inwide
About 16 in tall and 16 in wide at maturity: knee-high beside an adult.

See Wood's Blue 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 Wood's Blue

Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.

Space Wood's Blue about 16 in apart, center to center, so each plant has room to reach its full width.

Plant them
16 in apart
Per 10 sq ft
about 6
4 by 8 ft bed
about 18

Add Wood's Blue 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

Wood's Blue'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 9 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.

  • Missouri Botanical GardenPlant Finderheight, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases and pests
  • sandysplants.comSandy's Plantsheight, spread, hardiness zones, water, bloom months and color, soil, diseases and pests
  • RHSheight, spread, water, years to mature size, soil, diseases and pests
  • colesvillenursery.comColesville Nurseryheight, hardiness zones, trait tags, soil, diseases and pests
  • perennialfarmmarketplace.comPerennial Farm Marketplaceheight, hardiness zones, sun, bloom months and color and diseases
  • campbellsnursery.comCampbell's Nurseryheight, spread, sun, trait tags and diseases
  • michlers.comMichler's Florist, Greenhouses & Garden Designheight, bloom months and color and trait tags
  • NC State ExtensionPlant Toolboxsun and diseases
  • American Meadowstoxicity

How the checking works, and what each standard covers, is on the verified plants page.

The Aster group

One of 12 in the Aster group. Same genus, similar care.

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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.

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