Light Needs
Mature Height
Mature Spread
Growing Zones
Red Knock Out Rose (Rosa ‘Radrazz’) is the original award-winning Knock Out variety that revolutionized rose gardening. Known for its continuous flush of rich red blooms from spring until frost, this shrub rose provides non-stop color throughout the growing season. New foliage emerges with a reddish tint before maturing to deep green, then transitions to a rich purple hue in fall, adding multi-season interest.
Unlike traditional roses, the Red Knock Out Rose is nearly maintenance-free, with excellent resistance to black spot and other common rose diseases. Its long bloom season, easy care, and outstanding garden performance make it one of the most rewarding roses for both new and experienced gardeners. Perfect for accents, foundations, borders, or mass plantings, this rose brings dependable beauty and resilience to any landscape.
Red Knock Out Rose Care
Plant in well-drained soil and water deeply during establishment. Once established, water as needed when the soil becomes dry. Mulching around the base helps retain moisture and suppress weeds. Deadheading spent flowers encourages repeat blooms, while annual pruning in late winter or early spring maintains a tidy shape and promotes healthy new growth.
Red Knock Out Rose Growth & Spacing
This rose typically grows 3–4 feet tall and wide with a rounded, bushy form. For shrub borders or mass plantings, space plants 5–6 feet apart on center.
Why Grow Red Knock Out Rose?
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Continuous color – bright red blooms from spring to frost
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Low maintenance – disease-resistant and easy to grow
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Seasonal interest – attractive foliage in spring, summer, and fall
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Versatile uses – excellent for borders, foundations, or group plantings
If you’re searching for a hardy, long-blooming shrub rose that thrives with minimal care, the Red Knock Out Rose is a garden favorite you can rely on year after year.
Red Knock Out Rose Plant Facts
| USDA Hardiness Zones: 5-11 |
| Flower Color(s): Cherry Red |
| Bloom Period: Spring to First Frost |
| Foliage Color(s): Deep Purplish Green |
| Exposure: Full Sun |
| Height: 3-4 Feet Tall |
| Spread: 3-4 Feet Wide |
| Spacing: 3-4 Feet Center on Center |
| Habit: Bushy |
| Blooms On: New Wood |
| Watering: Drought Tolerant |
| Shrub Type: Deciduous |
| Scientific Name: Rosa x ‘Radrazz’ |
| Common Name: Red Knock Out Rose |
| Brand: Knock Out Roses |
| Root Stock: Grafted For Consistent Performance |
Please Note: The pictures below are to give a general representation of the different container sizes. The actual size/ages of plants are estimates and will vary based on type of plant, time of year, last pruning & many other factors.
Also Known As:
Quart
Plant Age:
~ 6 months - 1 year
Plant Size:
~ 4"-8"
Pot Size:
~ 4.75"H x 4.5"W
Volume:
1.50 quarts
Also Known As:
2.5 Quart Pot
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 8"-12"
Pot Size:
~ 6.5"H x 6.5"W
Volume:
2.20-2.30 quarts
Also Known As:
#1 Container
1 Gallon
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 10"-14"
Pot Size:
~ 7"H x 7.75"W
Volume:
2.26-3.73 quarts
Also Known As:
#2 Container
2 Gallon
Plant Age:
~ 1.5 - 3 years old
Plant Size:
~ 12"-18"
Pot Size:
~ 9.5"H x 9.5"W
Volume:
1.19-1.76 gallons
Also Known As:
#3 Container
3 Gallon
Plant Age:
~ 2 - 4 years old
Plant Size:
~ 12"-30"
Pot Size:
~9.5"H x 11"W
Volume:
2.32-2.76 gallons
Also Known As:
#5 Container
5 Gallon
Plant Age:
~3-4 years old
Plant Size:
~ 20" - 60"
Pot Size:
~11" H x 10 1/2” W
Volume:
3.5 - 4 gallons
We stand behind our plants with industry-leading guarantees to give you peace of mind.
We want your plants to arrive in great condition! If you notice any issues upon delivery, contact us within 3 days.
Starting January 1, 2026 all bushes, perennials & trees purchased come with an extended 1-year warranty for added confidence. If your plant dies due to a health issue within a year, we’ll make it right.
Pre-ordered plants are scheduled to ship in Spring 2026. We carefully plan our shipping dates based on your USDA Plant Hardiness Zone to ensure optimal planting conditions upon arrival. Want it sooner/later? Reach out, and we'll try our best to accommodate.
Estimated ship week for pre-ordered plants will ship based on growing zones as shown below.
| Growing Zone | Estimated Ship Week |
|---|---|
| Zone 10 | March 30th |
| Zone 9 | March 30th |
| Zone 8 | April 6th |
| Zone 7 | April 13th |
| Zone 6b | April 20st |
| Zone 6a | April 27th |
| Zone 5b | May 4th |
| Zone 5a | May 11th |
| Zone 4 | May 18th |
| Zone 3 | May 25th |
Note: These are only estimated ship dates. Plants may ship out later depending on weather & growing conditions of the plant.
Note: Only plants indicated as pre-order will ship as shown above. All other plants and hard goods will ship as normal.
Plants that are currently in stock typically ship within 2-7 business days after your order is placed.
Plant Addicts ships to the lower 48 states within the U.S. Unfortunately, we do not currently ship to Alaska, Hawaii, or internationally.
This plant cannot be shipped to the following states: AK, HI. These restrictions apply only to this specific plant due to agricultural regulations or other limitations. Other plants may still be available for shipping to these states.
If you have any questions about shipping restrictions, feel free to reach out to our team!