Illustration
White Lights
Rhododendron 'White Lights'
White Lights blooms from May through June.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing White Lights
Plant it in part shade. It prefers moderate water. It is hardy in USDA zones 4–7. Expect it to reach about 4 ft tall and 4 ft wide at maturity, in roughly 4 years (a house reading).
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 White Lights
Plant White Lights 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 4 to 7, spring means April to June and fall means August or September. Once settled, it blooms from May to June.
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 White Lights get?
4 fttall5 ft 7 inan adult4 ftwideSee White Lights 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 White Lights
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space White Lights about 4 ft apart, center to center, so each plant has room to reach its full width.
Add White Lights 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
White Lights' height, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases, pests and toxicity were checked against 16 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
- Chicago Botanic GardenGlencoe, Illinoisheight, spread, hardiness zones, sun, water, bloom months and color, soil and diseases
- RHSRoyal Horticultural Societyheight, spread, water, bloom months and color, trait tags and soil
- The Morton Arboretumheight, hardiness zones, sun, water, trait tags, soil and diseases
- horsfordnursery.comHorsford Gardens and Nursery (Charlotte, Vermont)height, spread, hardiness zones, bloom months and color and trait tags
- Iowa State University Extensionand Outreach, Yard and Gardenheight, bloom months and color, soil and pests
- rhododendron.orgAmerican Rhododendron Society, Azalea Hybrid Plant Description registe...height, hardiness zones, bloom months and color and trait tags
- NC State Extensiongenus pagesoil, diseases, pests and toxicity
- Pleasant Run Nurseryheight, spread, hardiness zones and sun
- campbellsnursery.comCampbell's Nursery (Lincoln, Nebraska)spread and bloom months and color
- arb.umn.eduUniversity of Minnesota Landscape Arboretum, Azalea Trial Garden (Chas...bloom months and color
- mnhardy.umn.eduUniversity of Minnesota, Minnesota Hardy (the breeder)height and diseases
- scholar.lib.vt.eduJournal American Rhododendron Society 40(3), Moe and Pellett, Universi...height and spread
- ASPCAAnimal Poison Controltoxicity
- ASPCAAnimal Poison Controltoxicity
- ASPCAAnimal Poison Controltoxicity
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about White Lights
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
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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.