Light Needs
Mature Height
Mature Spread
Growing Zones
Deep red to rich pink blooms packed with 30–35 petals give Triple Knock Out® Rose the full, classic look of a traditional garden rose with the easy-care performance that made Knock Out® Roses famous. Rosa ‘Radtriple’ grows into a compact, bushy shrub about 3 feet tall and 2–3 feet wide. The flowers appear repeatedly from spring through frost and carry a noticeable sweet floral fragrance, adding another dimension to a rose already loaded with color.
Triple Knock Out® is the first Grandiflora introduced into the Knock Out® Family of Roses, and its fuller flowers are what really set it apart. Each bloom has roughly three times the petals of the original Knock Out® Rose, creating a layered, traditional rose shape without bringing back the demanding maintenance often associated with classic roses. Exceptional disease resistance helps keep the medium-green foliage looking clean throughout the growing season, while reliable reblooming keeps new flowers coming with minimal upkeep.
Its compact habit makes Triple Knock Out® easy to use throughout the landscape. Plant several together for a flowering hedge or mass planting, feature one near an entry or patio where you can enjoy the fragrance, or mix it with perennials and other flowering shrubs. It also works well in larger containers when you want the appearance and fragrance of a traditional rose without committing to a high-maintenance rose garden.
Triple Knock Out® Rose Care
Grow Triple Knock Out® Rose in full sun for the strongest flowering and healthiest growth. Choose a location with well-drained soil and plant with the top of the root ball level with the surrounding ground. Water deeply and regularly while the plant establishes its root system. Once established, it has good drought tolerance, although occasional deep watering during extended dry periods will help maintain flowering and healthy growth.
Apply a balanced or rose fertilizer in early spring as new growth begins. Triple Knock Out® does not require routine deadheading to continue blooming, making it considerably easier to maintain than many traditional garden roses. Prune in late winter or early spring before new growth takes off, removing damaged or crossing branches and cutting the plant back as needed to maintain its compact shape. A layer of mulch around the root zone helps conserve moisture, suppress weeds, and protect roots through temperature swings.
Triple Knock Out® Rose Spacing
Space Triple Knock Out® Roses about 2–3 feet apart, depending on whether you want individual specimens or a fuller continuous planting. Its mature size of approximately 3 feet tall and 2–3 feet wide makes it easy to fit into foundation beds, borders, and smaller garden spaces. For container growing, choose a large pot with excellent drainage and enough room for the root system to develop. Pair it with catmint or salvia for contrasting blue-purple flowers, ornamental grasses for added texture, or white-flowering perennials to make its deep red-to-pink blooms stand out.
What’s the Difference Between Red Knock Out® Roses?
Compare Triple Knock Out®, Double Knock Out®, and the original Knock Out® to find the flower style and size that fits your garden.
Triple Knock Out® Rose
Full, layered flowers with a traditional rose look.
- Size 3' H × 2–3' W
- Hardiness Zones 4b–11
- Fragrance Sweet Floral (Strongest)
- Rose Style Grandiflora
Double Knock Out® Rose
Fuller flowers with a more traditional rose look.
- Size 3–4' H × 3–4' W
- Hardiness Zones 5–11
- Fragrance Fruity, Sweet
- Rose Style Landscape Shrub Rose
Knock Out® Rose
The original with simple, open flowers.
- Size 3–4' H × 3–4' W
- Hardiness Zones 5–11
- Fragrance Subtle Sweet
- Rose Style Landscape Shrub Rose
Triple Knock Out® Rose Information
| USDA Hardiness Zones: 4b - 11 |
| Plant Type: Bushes |
| Light Exposure: Full Sun (At Least 6 Hours of Direct Sunlight) |
| Mature Height: 3 Feet |
| Mature Spread: 2 - 3 Feet |
| Spacing: 2 - 3 Feet |
| Habit: Compact, Bushy |
| Flower Color(s): Red, Deep Pink |
| Flower Description: Full, Double Blooms With 30 - 35 Petals |
| Bloom Period: Spring to Frost |
| Foliage Type: Deciduous |
| Foliage Color(s): Medium Green |
| Foliage Description: Disease Resistant |
| Seasonal Interest: Spring Flowering, Summer Flowering, Fall Flowering |
| Watering: Average |
| Resists: Disease |
Simple Plant Spacing Calculator
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 | April 6th |
| Zone 9 | April 6th |
| 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: ID, 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!