How to Grow Krossa Regal

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Krossa Regal

Hosta 'Krossa Regal'

flower

Krossa Regal is an award-winning hosta cultivar prized for its striking upright, vase-shaped form and blue-green foliage with prominent white margins. It produces tall lavender flower spikes in mid to late summer that rise well above the foliage. This is one of the most architectural and elegant hostas available, making it a specimen plant for shaded gardens.

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Example Krossa Regal timeline · Pittsburgh, PA (Zone 6b)

Plant Krossa Regal
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
First Krossa Regal blooms
Mid-to-late summer

Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Krossa Regal dates for your own zip code.

Growing Conditions

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Sun: Partial to full shade; 2-4 hours of dappled or morning sun; avoid hot afternoon sun which bleaches foliage

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Water: Keep consistently moist but not waterlogged; water deeply 1-2 times weekly during growing season; more frequent in hot, dry periods; drought-tolerant once established but performs best with regular moisture

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Spacing: 24 inches

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Days to maturity: 3-5 years to reach full mature size and form

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Planting depth: Crown at or slightly above soil level; plant to same depth as nursery container

Soil

Type: Well-draining loamy soil rich in organic matter

pH: 6.0-7.0

Amendments:

Compost aged leaf mold peat moss slow-release fertilizer

Growing Zones

Find your zone →

Thrives in zones 3-8; best performance in zones 4-7

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b

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Growth Stages

Establishment

First year

Young plant has small tight clump with juvenile foliage; upright habit begins forming immediately

Water regularly; apply 2-3 inches of mulch around base; do not divide for at least 2-3 years; remove flower spikes first year to encourage foliage growth

Vegetative Growth

Years 2-3

Clump expands and develops characteristic upright vase form; variegated foliage becomes more prominent with blue-green centers and white margins clearly defined

Maintain consistent moisture; apply balanced fertilizer in spring; mulch annually; can begin allowing flowers after first season; thin out internal shoots to maintain upright form if desired

Pre-flowering

Mid-summer approaching

Mature clump reaches near full size and form; dense upright growth habit is well-established; foliage color is vibrant and variegation is most pronounced

Continue consistent watering and fertilizing; watch for emerging flower buds in mid-summer; foliage remains attractive throughout season

Flowering

4-6 weeks (July-August)

Tall scapes (flower stems) emerge from center of clump, rising 2-4 feet above foliage; small lavender to pale purple flowers arranged in dense raceme spikes

Flowers emerge mid to late summer; support tall scapes if in windy location; deadhead spent flowers or leave for ornamental winter interest; flowers attract pollinators and hummingbirds

Dormancy

November-March

Foliage yellows and dies back in fall; clump goes completely dormant underground through winter; dried seed heads may remain on plant

Cut back dead foliage in late fall or early spring; apply fresh mulch layer before winter; no watering needed; do not disturb crown; plant re-emerges in spring as new shoots

Companion Planting

Plan your garden →

Plant with:

Astilbe Japanese painted fern Brunnera Hellebore Coral bells Solomon's seal Bleeding heart Liriope

Avoid planting near:

Aggressive spreading groundcovers Competitive perennials requiring full sun Plants requiring frequent disturbance

Common Pests

and (Limax and Limax maximus)
Hand-pick early morning or evening; remove plant debris and mulch thickness; beer traps; copper barriers; nematodes; avoid overwatering; diatomaceous earth
Spray with strong water stream; insecticidal soap; neem oil; encourage natural predators; usually not damaging to established plants
Hand-pick into soapy water; Japanese beetle traps placed away from hostas; neem oil; pyrethrin-based insecticides
Improve soil drainage; avoid overwatering; remove affected portions; ensure crown stays at or above soil level; treat with fungicide if severe

Uses

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Architectural Specimen Plant

Household

Krossa Regal's distinctive upright, vase-shaped form makes it an outstanding focal point in shade gardens, woodland borders, or container plantings. Its formal structure provides year-round visual interest and works exceptionally well in contemporary, Japanese-inspired, or cottage garden designs. [source]

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Pollinator Attraction

Wildlife

The tall lavender flower spikes attract hummingbirds, bees, and other pollinators in mid-summer, providing late-season nectar sources. The flowers are mildly fragrant and support various beneficial insects. [source]

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Floral Arrangements

Craft

The tall, slender flower scapes can be cut and used in fresh floral arrangements or dried for permanent displays. The lavender blooms pair well with other shade garden flowers and greenery. [source]

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Traditional Asian Medicine

Medicinal

Hostas have been used in traditional Chinese and Japanese herbal medicine for various purposes including supporting digestive health. Some cultures consume young shoots as a seasonal delicacy. [source]

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Edible Shoots

Culinary

Young emerging shoots are edible with a mild asparagus-like flavor and are foraged or cultivated in Japan as a seasonal vegetable called 'urui'. The shoots should be harvested early and cooked before the leaves unfurl. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Hostas are ornamental foliage plants not typically harvested. Enjoy the upright form and variegated foliage throughout growing season. Flower scapes can be cut for arrangement in summer. Let foliage mature fully before cutting back in fall.

Fun Facts

🌱 Krossa Regal won the Hosta of the Year award from the American Hosta Society in 1990 and has remained one of the most popular hosta cultivars worldwide.
🌱 The distinctive upright growth habit of Krossa Regal is unusual among hostas and makes it particularly useful in small spaces where ground-hugging varieties would be less effective.
🌱 Hosta plants can live for decades and even centuries, with mature clumps sometimes reaching impressive sizes and being passed down through generations of gardeners.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Annual Crown Cultivar Deadhead Mulch

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