Girard's Crimson (Rhododendron 'Girard's Crimson') - red flowers, illustrated plant cardIllustration

Girard's Crimson

Rhododendron 'Girard's Crimson'

Girard's Crimson blooms from April through May.

Bloom calendar
Bloom time
Apr–May
checked
Hardiness
Zones 5–8
checked
Sun
Part shade
checked
Water
Moderate water
checked
Mature size
3 ft × 3.5 ft
checked
Type
Shrub
house classification

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

Growing Girard's Crimson

Plant it in part shade. It prefers moderate water. It is hardy in USDA zones 5–8. Expect it to reach about 3 ft tall and 3.5 ft wide at maturity, in roughly 4 years (checked).

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 6 sources it was checked against

When to plant Girard's Crimson

Plant Girard's Crimson 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 5 to 8, spring means March to May and fall means August or September. Once settled, it blooms from April to May.

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 Girard's Crimson get?

Illustration of Girard's Crimson drawn to scale beside an adult3 fttall5 ft 7 inan adult3.5 ftwide
About 3 ft tall and 3.5 ft wide at maturity: waist-high beside an adult.

See Girard's Crimson 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 Girard's Crimson

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

Space Girard's Crimson about 3.5 ft apart, center to center, so each plant has room to reach its full width.

Plant them
3.5 ft apart
Per 10 sq ft
one needs about 12 sq ft
4 by 8 ft bed
about 2

Add Girard's Crimson 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

Girard's Crimson'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 6 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
  • NC State Extensiondedicated cultivar page for this plant, distinct from the group page u...height, spread, hardiness zones, water, bloom months and color, trait tags, soil, diseases, pests and toxicity
  • rhododendron.orgAmerican Rhododendron Society (Azalea Hybrid Plant Description registe...height, hardiness zones, bloom months and color, years to mature size and trait tags
  • medfordnursery.comMedford Nursery (wholesale grower, plant profile)height, spread, hardiness zones and sun
  • poplarforestnursery.comPoplar Forest Nurseryheight, spread and hardiness zones
  • ASPCAtoxicity

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

Good to know about Girard's Crimson

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

Safety

All parts contain grayanotoxins. Toxic to dogs, cats and horses: vomiting, diarrhea, weakness, and in serious cases cardiac failure. Pets and livestock are poisoned more readily than people. per ASPCA

The Azaleas group

One of 16 in the Azaleas 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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