Phantom Hydrangea (Hydrangea paniculata 'Phantom') - white flowers, illustrated plant cardIllustration

Phantom Hydrangea

Hydrangea paniculata 'Phantom'

Also called panicle hydrangea

Phantom Hydrangea blooms from July through September.

Bloom calendar
Bloom time
Jul–Sep
checked
Hardiness
Zones 3–8
checked
Sun
Full sun
checked
Water
Moderate water
checked
Mature size
6.5 ft × 7.5 ft
checked
Type
Shrub
house classification

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

Growing Phantom Hydrangea

Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 3–8. Expect it to reach about 6.5 ft tall and 7.5 ft wide at maturity, in roughly 4 years (a house reading).

Verification
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.

See the 12 sources it was checked against

When to plant Phantom Hydrangea

Plant Phantom Hydrangea 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 July to September.

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 Phantom Hydrangea get?

Illustration of Phantom Hydrangea drawn to scale beside an adult6.5 fttall5 ft 7 inan adult7.5 ftwide
About 6.5 ft tall and 7.5 ft wide at maturity: a little taller than an adult.

See Phantom Hydrangea 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 Phantom Hydrangea

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

Space Phantom Hydrangea about 7.5 ft apart, center to center, so each plant has room to reach its full width.

Plant them
7.5 ft apart
Per 10 sq ft
one needs about 56 sq ft
4 by 8 ft bed
about 1

Add Phantom Hydrangea 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

Phantom Hydrangea's height, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases, pests and toxicity were checked against 12 published sources on August 2, 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.

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

Good to know about Phantom Hydrangea

Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.

Safety

Toxic to dogs, cats and horses; the leaves and buds hold a cyanogenic glycoside. Eating it mostly causes vomiting and diarrhea. per ASPCA

The Hydrangeas group

One of 17 in the Hydrangeas 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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