Garden hybrid

This is a garden hybrid, bred from more than one wild species, so it has no single species page of its own.

298 other cultivars

perennial

Hosta Knockout

Hosta x hybrida 'Knockout'

The Story

Plant Bio

Hosta 'Knockout' is a deciduous perennial forming a dense mound of heart-shaped, dark green leaves with narrow, creamy-white margins. Spikes of bell-shaped, lavender flowers appear in mid-summer.

This cultivar is valued for its crisp variegation and vigorous growth, creating a striking, medium-sized clump in the shade garden.

Uses & Benefits:

Adds lush greenery and variegated foliage, thrives in shaded garden beds.

Provides ground cover, suppresses weeds in shaded areas.

Supports beneficial insects and contributes to biodiversity in shaded habitats.

Garden hybrid

Bred from more than one wild species, so it has no species page of its own.

Essentials

At a Glance

Plant Type

Perennial

Height

18 inches

Width

30 inches

Light

Partial Sun, Shade

Zones

4, 5, 6, 7, 8, 9

Water

Prefers consistently moist soil

Humidity

Moderate to high

Lifespan

Perennial

Native To

Northeast Asia

Toxicity

Toxic to dogs, cats, and horses

Bloom period

Mid-summer – Late summer

In flower about 2 months of the year

Planting

How to Grow

Choose a shaded spot with well-draining soil
Tuck seeds or divisions into prepared soil in early spring
Water thoroughly to establish roots within 2 weeks
Mulch around plants to retain moisture and suppress weeds
Fertilize in early spring with a balanced fertilizer
Divide every 3-4 years to maintain vigor

Pro Tip

Ensure soil remains consistently moist for optimal growth

Keep It Thriving

Care Guide

Do

Water regularly during dry spells 🌱
Apply mulch to conserve moisture
Divide every few years to prevent overcrowding
Fertilize in spring for lush foliage

Don't

Avoid overwatering to prevent root rot ❌
Don’t expose to harsh afternoon sun
Refrain from neglecting mulching
Avoid heavy fertilization in late fall

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Deadhead
Divide
Fertilize
Mulch
Pest Check
Spring Cleanup

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Shaded border with vibrant foliageWoodland garden accent

Companion Plants

Ferns Astilbe Hosta sieboldiana HeucheraJapanese forest grass

Multiply

Propagation Methods

Good to Know

Common Questions

Hosta Knockout questions

What zones can Hosta Knockout grow in?

Hosta Knockout is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Hosta Knockout deer resistant?

Not reliably. Deer may browse Hosta Knockout, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Hosta Knockout bloom?

Hosta Knockout typically blooms in mid-summer through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Hosta Knockout need full sun?

Hosta Knockout does best in part shade.