Illustration
Krossa Regal
Hosta 'Krossa Regal'
Krossa Regal is grown for its foliage rather than flowers, giving the garden structure and color all season long.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Krossa Regal
Plant it in full shade. It prefers moderate water. It is hardy in USDA zones 3–8. Expect it to reach about 3 ft tall and 3.5 ft wide at maturity, in roughly 3 years (not yet checked).
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. 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 Krossa Regal
Plant Krossa Regal 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.
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 Krossa Regal get?
3 fttall5 ft 7 inan adult3.5 ftwideSee Krossa Regal 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 Krossa Regal
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Krossa Regal about 3.5 ft apart, center to center, so each plant has room to reach its full width.
Add Krossa Regal 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
Krossa Regal's height, spread, hardiness zones, sun and trait tags were checked against 3 published sources on July 29, 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 Gardenheight, spread, hardiness zones, sun and trait tags
- Plant Delights Nurseryheight, spread, hardiness zones and sun
- Chicago Botanic GardenPlant Finderhardiness zones and sun
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Krossa Regal
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Safety
Toxic to dogs, cats and horses. All parts contain saponins; eating it causes vomiting, diarrhea and depression (lethargy). per ASPCA and NC State
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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.