Illustration
Dark Knight Bluebeard
Caryopteris × clandonensis 'Dark Knight'
Also called dark knight caryopteris and dark knight blue mist
Dark Knight Bluebeard blooms from August through September.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Dark Knight Bluebeard
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 5–9. Expect it to reach about 2.5 ft tall and 2.5 ft wide at maturity, in roughly 4 years (a house reading).
No toxicity note is on file for Dark Knight Bluebeard. That is not a clearance: check its safety for people and pets before planting.
What was checked
Mature height and spread, hardiness zones, sun, water, bloom months and color and the trait tags were checked against named botanical sources for this plant, with what the sources could not settle written down; years to mature size rests on a recorded house rule where no publisher states one, and is marked so; its common name and alternate names have not been checked yet. 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 Dark Knight Bluebeard
Plant Dark Knight Bluebeard 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 7, the middle of its hardy zones 5 to 9, spring means March to May and fall means September or October. Once settled, it blooms from August to September.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 7, the middle of this plant's hardy range, start with zone 7 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Dark Knight Bluebeard get?
2.5 fttall5 ft 7 inan adult2.5 ftwideSee Dark Knight Bluebeard 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 Dark Knight Bluebeard
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Dark Knight Bluebeard about 2.5 ft apart, center to center, so each plant has room to reach its full width.
Add Dark Knight Bluebeard 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
Dark Knight Bluebeard's height, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases, pests and toxicity were checked against 10 published sources on September 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 GardenPlant Finderheight, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases and pests
- Plant Addictsheight, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil and pests
- plants.thegrowingplace.comThe Growing Place (NetPS Plant Finder entry)height, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil and pests
- RHSRoyal Horticultural Societyheight, spread, sun, water, bloom months and color, soil, diseases and pests
- Chicago Botanic Gardenarchived entryheight, hardiness zones, sun, water and bloom months and color
- cutflowers.ces.ncsu.eduNC State Extension, ASCFG cut flower trial reporthardiness zones, bloom months and color and pests
- NC State ExtensionCaryopteris x clandonensis, hybrid pagesun, soil, diseases and pests
- The Morton Arboretumhybrid page, 'Dark Knight' cultivar blockheight and spread
- ASPCAPopular Fall Plants: Which Ones Are Pet-Friendly?toxicity
- Plant AddictsAre Bluebeard Poisonous?, a genus-level articletoxicity
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.