shrub

Radrazz Knock Out Rose

Rosa 'Radrazz'

The Story

Plant Bio

Shrub roses are a diverse group known for their hardiness, repeat blooming, and often lower maintenance requirements compared to hybrid teas. They are valued for their landscape utility.

'Radrazz', the original Knock Out® Rose, revolutionized the rose market with its exceptional resistance to black spot and other common rose diseases. It blooms prolifically in cycles from spring to frost and is 'self-cleaning,' meaning it drops its spent petals cleanly without deadheading.

Uses & Benefits:

The Knock Out® Rose provides an almost non-stop display of cheerful cherry-red flowers from late spring until the first hard frost. Its foliage is an attractive dark, glossy green and remains clean and healthy-looking all season.

Its primary practical benefit is its low-maintenance nature. It requires no deadheading and minimal spraying for diseases, making it an accessible plant for beginner gardeners or those who want the beauty of roses without the traditional fuss.

The single-petaled flowers of the original 'Radrazz' are accessible to pollinators like bees, providing a long season of pollen. The dense, thorny growth can also offer shelter for small birds.

Essentials

At a Glance

Plant Type

Shrub

Height

42 inches

Width

42 inches

Light

Full Sun

Zones

5, 6, 7, 8, 9

Water

Moderate

Humidity

Adaptable

Lifespan

10-15 years

Native To

Hybrid

Toxicity

Non-toxic, but thorns can cause injury.

Bloom period

Late spring – Mid-fall

In flower about 6 months of the year

Planting

How to Grow

Select a location with at least 6-8 hours of direct sun daily.
Amend soil with compost to ensure rich, well-drained conditions.
Dig a hole large enough to accommodate the roots comfortably.
For grafted roses, position the bud union at or just above the soil level.
Backfill the hole, gently firming the soil around the roots.
Water thoroughly and apply a layer of mulch.

Pro Tip

For best performance, give them a hard prune to about 12-18 inches in early spring, just as the buds begin to swell.

Keep It Thriving

Care Guide

Do

Provide consistent water, especially during hot, dry weather.
Ensure good air circulation to maximize its disease resistance.
Fertilize regularly through the growing season for best bloom production.
Prune annually to maintain a compact, bushy shape and encourage new growth.

Don't

Do not plant in a shady or waterlogged location.
Avoid overhead watering, which can encourage disease on less resistant roses.
Don't worry about deadheading; it's not necessary for continuous bloom.
Do not plant in areas with known Rose Rosette Disease without careful monitoring.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Pest Check
Plant
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Continuous color in a low-maintenance hedgeMass planting for a bold impactEasy-care accent in mixed perennial borders

Companion Plants

Nepeta x faassenii 'Walker's Low'Salvia nemorosa 'Caradonna'Lavandula angustifolia 'Hidcote'Geranium 'Rozanne'Calamintha nepeta 'White Cloud'

Multiply

Propagation Methods

Good to Know

Common Questions

Radrazz Knock Out Rose questions

What zones can Radrazz Knock Out Rose grow in?

Radrazz Knock Out Rose is hardy in USDA Zones 5–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Radrazz Knock Out Rose deer resistant?

Not reliably. Deer may browse Radrazz Knock Out Rose, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Radrazz Knock Out Rose bloom?

Radrazz Knock Out Rose typically blooms in late spring through mid-fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Radrazz Knock Out Rose need full sun?

Radrazz Knock Out Rose does best in full sun (6+ hours).

Is Radrazz Knock Out Rose drought tolerant?

Yes — once established (usually after the first full season), Radrazz Knock Out Rose handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.