Knock Out

Double Knock Out® Rose Bush

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Size
$68.00

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Once a weekFull sunSummer to fall
  • Vibrant Double Blooms: Features abundant, double-flowered red blooms that offer a continuous show of color and texture in the garden.
  • Exceptional Disease Resistance: Bred for robust health, this rose bush resists common rose diseases, keeping the garden vibrant and healthy with minimal intervention.
  • Self-Cleaning and Drought Tolerant: Requires no deadheading to maintain its bloom cycle and demonstrates significant drought resistance once established, simplifying care and upkeep.

More Details

The Double Knock Out Rose Bush, known scientifically as ‘Radtko’ PP 16,202 CPBR 3,104, revolutionizes the ease of care and continuous beauty in the world of roses. This variety stands out with its full, vibrant red blooms that enrich any garden from early summer until the first frost. Distinguished by its exceptional disease resistance, particularly to black spot and powdery mildew, the Double Knock Out Rose ensures a lush display with minimal maintenance. Its compact growth habit makes it ideal for a variety of landscape uses, including borders, hedges, or as a striking specimen. Gardeners will appreciate its drought tolerance and self-cleaning flowers, making it a perfect choice for those seeking long-lasting color with little fuss.

Growth rate: Moderate growth rate; typically reaches 3-4 feet in height and width, making it a versatile size for various garden applications.

Please note: Images on our website depict plants and trees at full maturity to showcase their expected grown characteristics. These images are illustrative examples only and do not represent the size of plants or trees upon delivery.

Pruning: Prune in late winter or early spring, removing any dead or damaged wood and shaping the bush as desired to encourage healthy growth and blooms.

Fertilization: Apply a balanced, slow-release fertilizer designed for roses in early spring to kickstart annual growth and flowering.

Winter Protection: In colder zones, apply a layer of mulch around the base to protect the roots during winter.


Plant in spring or fall. Choose a sunny spot with well-draining soil. Dig a hole as wide and slightly deeper than the root ball. Remove the plant from its container, gently loosen the roots, and place it in the hole, ensuring the graft point is just above soil level. Backfill with soil, water thoroughly, and apply a layer of mulch to conserve moisture and suppress weeds. Space plants 3-4 feet apart to allow for mature growth.

Water deeply and regularly during the first growing season to establish an extensive root system. Once established, reduce frequency but ensure the plant receives adequate moisture, particularly during dry spells, to maintain its vibrant display. Flourishes in full sun, requiring at least 6-8 hours of direct sunlight daily to produce the most vigorous growth and abundant blooms.

We process and ship your order as quickly as possible, typically within 1-3 business days. You will receive a shipping confirmation with tracking information once your item(s) ship.

We have perfected packaging and shipping plants & trees! That is why we DO NOT use any third-party fulfillment like most other online retailers. Your trees go straight from our farm to your door, safely packaged by our team of seasoned professionals. Our process ensures your plants leave our facility and arrive to your door in the best condition possible!

In cases of extreme cold or hot weather, we may temporarily delay shipping to ensure the well-being of your plants. Our primary focus is on delivering healthy and thriving plants to you. Rest assured, we'll make every effort to notify you of any delays promptly.

Please allow additional ship times during inclement weather and sale periods. We do not process or ship orders on the weekend or U.S. Holidays. Simply Trees is not responsible for delays due to carriers, local disruptions, or weather.

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At Simply Trees, we're committed to your satisfaction. If your plants arrive considerably damaged or sustained damage beyond the point of recovery, please contact us within five days at sales@simplytrees.store with clear photos for assistance. Our 30-day guarantee covers issues after planting, subject to our terms and conditions. We can't cover plants in the wrong climate or with inadequate care, but we're here to help in other situations. For a detailed understanding of our 30-day guarantee and how we ensure a fair process, click here to learn more.

USDA GROW ZONE:

Zones 5-11

The Double Knock Out Rose Bush is hardy and adaptable across a wide range of climates in USDA Zones 5-11, thriving in full sun and well-drained soil. Its resilience to extreme temperatures, coupled with its disease resistance, makes it a reliable and spectacular addition to gardens nationwide. Whether planted as a standalone feature or part of a mixed border, ‘Radtko’ brings beauty and ease to gardening efforts, requiring only basic care to flourish and impress.

Frequently Asked Questions

The Double Knock Out Rose bush typically grows to a mature size of about 3 to 4 feet in height and width. However, the exact size of a Double Knock Out Rose bush can vary depending on several factors, including climate, soil conditions, and care practices.

In optimal growing conditions with plenty of sunlight, well-draining soil, and regular watering and fertilizing, Double Knock Out Rose bushes can achieve their maximum size more quickly. Conversely, factors such as poor soil drainage, inadequate sunlight, or neglecting regular maintenance tasks like pruning can result in smaller plant sizes.

It's worth noting that Double Knock Out Rose bushes are known for their relatively compact growth habit compared to other types of roses, making them well-suited for smaller garden spaces, borders, or containers. Additionally, regular pruning and deadheading of spent blooms can help manage the size and shape of the bushes while promoting continuous blooming throughout the growing season.

Overall, Double Knock Out Rose bushes are prized for their manageable size, abundant blooms, and resilience, making them a popular choice for gardeners looking to add color and beauty to their landscapes.

The growth rate of Double Knock Out Rose bushes can vary depending on several factors, including climate, soil conditions, and care practices. However, these roses are known for their vigorous growth and relatively fast establishment compared to other rose varieties. Under optimal growing conditions, Double Knock Out Rose bushes can grow at a moderate to fast rate, typically reaching their mature size within a few growing seasons.

On average, Double Knock Out Rose bushes can grow anywhere from 1 to 2 feet in height and spread per year, especially during their active growing season in spring and summer. With proper care, including regular watering, fertilizing, and pruning, you can help encourage healthy growth and maximize the growth rate of your Double Knock Out Rose bushes.

It's important to note that while Double Knock Out Roses are fast-growing, they are also relatively compact compared to other types of roses, making them suitable for smaller garden spaces and containers. Additionally, regular maintenance, such as pruning and deadheading spent blooms, can help manage the growth and shape of the bushes while promoting continuous blooming throughout the growing season.

The best place to plant Double Knock Out Rose bushes is in a location that provides full sun exposure for at least six hours per day. Here are some considerations for selecting the ideal planting site:

Full Sun: Choose a spot in your garden that receives plenty of sunlight throughout the day. Double Knock Out Roses thrive in full sun, which helps promote vigorous growth and abundant blooming. Avoid planting in areas with partial shade, as this can result in fewer flowers and weaker growth.

Well-Drained Soil: Ensure the planting site has well-draining soil to prevent waterlogging, which can lead to root rot and other problems. Double Knock Out Roses prefer soil that is fertile, loamy, and well-aerated. If your soil is heavy clay or poorly drained, consider amending it with organic matter to improve its texture and drainage.

Air Circulation: Choose a location with good air circulation to help prevent fungal diseases such as powdery mildew and black spot. Avoid planting Double Knock Out Roses in areas where air tends to stagnate, such as against a solid fence or wall.

Space Considerations: Provide adequate spacing between Double Knock Out Rose bushes to allow for proper air circulation and future growth. Space plants at least 3 to 4 feet apart to prevent overcrowding and competition for resources.

Accessibility: Select a location that is easily accessible for watering, pruning, and other maintenance tasks. Avoid planting Double Knock Out Roses in areas that are difficult to reach or navigate, as this can make caring for the plants more challenging.

Aesthetic Considerations: Consider the overall aesthetic of your garden when choosing a planting site for Double Knock Out Rose bushes. These roses make excellent focal points or additions to mixed borders, flower beds, or containers, where their vibrant blooms can be appreciated.

By selecting a planting site that meets these criteria, you can create an ideal growing environment for Double Knock Out Rose bushes and enjoy their beauty and resilience in your garden.

Planting Double Knock Out Rose bushes is relatively straightforward and follows similar steps to planting other types of roses. Here's a guide to planting Double Knock Out Rose bushes:

Choose a Suitable Location: Select a planting site that receives full sun, meaning at least six hours of direct sunlight per day. Ensure the soil is well-draining and fertile, with a pH between 6.0 and 7.0.

Prepare the Planting Hole: Dig a hole that is twice as wide and slightly deeper than the root ball of the rose bush. Loosen the soil in the planting hole to encourage root growth.

Amend the Soil: If your soil is heavy clay or poor-draining, consider amending it with organic matter such as compost or aged manure to improve drainage and fertility. Mix the organic matter thoroughly into the backfill soil.

Remove the Rose from its Container: Gently remove the Double Knock Out Rose bush from its container, taking care not to damage the roots. If the roots are tightly bound, gently tease them apart with your fingers to encourage outward growth.

Plant the Rose: Place the rose bush in the center of the planting hole, ensuring that the top of the root ball is level with the surrounding soil surface. Backfill the hole with the amended soil mixture, gently firming it around the roots as you go to remove air pockets.

Water Thoroughly: After planting, water the rose bush thoroughly to settle the soil and ensure good root-to-soil contact. Continue to water regularly during the establishment period, keeping the soil evenly moist but not waterlogged.

Mulch the Soil: Apply a layer of organic mulch, such as shredded bark or compost, around the base of the rose bush to help retain soil moisture, regulate soil temperature, and suppress weed growth. Leave a few inches of space between the mulch and the base of the plant to prevent rotting.

Prune as Needed: While not necessary at planting time, you may choose to lightly prune the rose bush to remove any dead, damaged, or crossing branches. This helps promote healthy growth and shape the plant.

Monitor and Maintain: Keep an eye on your newly planted Double Knock Out Rose bush, watering as needed and providing appropriate care to encourage healthy growth and abundant blooming.

By following these steps, you can successfully plant Double Knock Out Rose bushes and enjoy their vibrant blooms in your garden for years to come.

The frequency of watering for a Double Knock Out Rose bush depends on several factors, including climate, soil type, and weather conditions. Here are some general guidelines to help you determine how often to water your Double Knock Out Rose bush:

Establishment Period: During the first year after planting, Double Knock Out Rose bushes require regular watering to establish a strong root system. Water deeply immediately after planting, and continue to provide consistent moisture, especially during dry spells or hot weather.

Soil Moisture: Check the moisture level of the soil regularly by inserting your finger into the soil near the base of the plant. Water the rose bush when the top inch or two of soil feels dry to the touch. Avoid watering if the soil feels moist, as overwatering can lead to root rot and other issues.

Weather Conditions: Adjust your watering schedule based on weather conditions. During hot and dry periods, the rose bush may require more frequent watering to maintain adequate soil moisture. Conversely, reduce watering during cooler and rainy periods to prevent waterlogged soil.

Morning Watering: Water the rose bush in the morning to allow the foliage to dry before evening. Wet foliage overnight can increase the risk of fungal diseases. Watering in the morning also ensures that the plant has access to moisture during the heat of the day.

Deep Watering: When watering, apply water directly to the root zone of the plant rather than overhead. Water deeply to encourage deep root growth and drought tolerance. Ensure that the water penetrates the soil to a depth of at least 6 to 8 inches.

Mulching: Apply a layer of organic mulch, such as shredded bark or compost, around the base of the rose bush to help retain soil moisture, regulate soil temperature, and suppress weed growth. Mulching also helps reduce water evaporation from the soil surface.

Container-Grown Roses: If your Double Knock Out Rose bush is planted in a container, check the soil moisture more frequently, as container plants may dry out more quickly than those planted in the ground. Water container-grown roses when the top inch of soil feels dry.

By monitoring soil moisture levels and adjusting your watering frequency based on the factors mentioned above, you can help ensure that your Double Knock Out Rose bush receives the right amount of water to thrive and produce beautiful blooms.

Double Knock Out Rose bushes do not spread in the same manner as some other plants, such as ground covers or invasive species. These roses are typically grown as shrubs and tend to maintain a relatively compact and upright growth habit. However, they can gradually increase in size over time through the growth of new stems and branches from the base of the plant, especially if left unpruned. While Double Knock Out Roses may not spread aggressively, it's essential to provide adequate spacing between plants when planting to accommodate their mature size and prevent overcrowding. Regular pruning can also help manage the size and shape of the bushes and prevent them from encroaching on nearby plants or structures. Overall, while Double Knock Out Rose bushes may exhibit some limited spreading as they grow, they are not considered invasive and can be easily controlled with proper maintenance and care.

Double Knock Out Rose bushes are known for their prolific and continuous blooming throughout the growing season. These roses are prized for their ability to produce an abundance of flowers from spring until the first frost in fall. The exact frequency of blooming can vary depending on various factors such as climate, growing conditions, and care practices. However, under optimal conditions, Double Knock Out Rose bushes can bloom every 5 to 6 weeks during the growing season. Deadheading spent blooms regularly can encourage the plant to produce new flowers continuously, extending the blooming period and maximizing the display of vibrant blooms in your garden.

While there is no strict rule about cutting back Double Knock Out Rose bushes in the fall, it's generally recommended to avoid heavy pruning during this time. Here are some considerations to keep in mind:

Late Season Blooms: Double Knock Out Roses often continue to produce blooms into the fall months. Pruning too heavily in the fall could remove potential flowering wood and reduce the number of blooms you enjoy before the end of the growing season.

Winter Protection: Leaving some of the foliage and canes intact over the winter can provide additional protection for the plant against cold temperatures and harsh weather conditions. The remaining foliage helps insulate the plant and prevent frost damage to the crown and roots.

Spring Pruning: Instead of heavy pruning in the fall, consider postponing major pruning until early spring, just before new growth begins. This allows you to assess the extent of winter damage and prune accordingly, promoting healthy growth and abundant blooms for the upcoming growing season.

Light Maintenance: While heavy pruning is not recommended in the fall, you can still perform light maintenance tasks such as removing spent blooms (deadheading) and shaping the bushes as needed. This helps maintain the plant's appearance without risking the removal of potential flowering wood.

Disease Prevention: Removing any diseased or damaged foliage and canes in the fall can help prevent the spread of diseases over the winter months. However, be cautious not to remove too much healthy wood, as this can impact spring growth and flowering.

Ultimately, the decision to prune Double Knock Out Rose bushes in the fall depends on your specific goals and the condition of the plants. If the bushes are healthy and still blooming, it may be best to postpone major pruning until spring. However, if there are diseased or damaged branches, light pruning to remove these issues can be beneficial. Always use sharp, clean tools when pruning, and avoid removing more than one-third of the plant's total size at any one time.

Several factors could contribute to Double Knock Out Rose bushes not blooming as expected. Here are some common reasons and solutions:

Pruning: Improper pruning can delay or inhibit blooming. Double Knock Out Roses bloom on new growth, so if they are pruned at the wrong time or too heavily, it can remove potential flowering wood. Ensure pruning is done in early spring before new growth starts, and avoid cutting back more than one-third of the bush's total size.

Nutrient Deficiency: Roses require specific nutrients, particularly nitrogen, phosphorus, and potassium, to bloom well. A deficiency in any of these nutrients can impact flowering. Test the soil to assess its nutrient levels, and amend it with a balanced fertilizer formulated for roses if deficiencies are detected.

Sunlight: Insufficient sunlight can reduce blooming. Double Knock Out Roses prefer full sun, meaning they need at least six hours of direct sunlight daily to thrive and bloom abundantly. If the bushes are planted in a shaded area, consider transplanting them to a sunnier location.

Overcrowding: If the bushes are overcrowded or planted too closely together, they may compete for nutrients and sunlight, resulting in reduced blooming. Ensure proper spacing between bushes to allow for adequate air circulation and light penetration.

Watering Issues: Inconsistent or inadequate watering can stress the bushes, leading to reduced blooming. Ensure the bushes receive sufficient water, especially during hot and dry periods. However, avoid overwatering, as waterlogged soil can also stress the plants.

Disease or Pest Infestation: Diseases such as powdery mildew or pests like aphids can affect the health of the bushes, leading to decreased blooming. Monitor the plants regularly for signs of disease or pest infestation, and take appropriate measures to control them, such as applying fungicides or insecticides as needed.

Environmental Stress: Environmental factors such as extreme heat or cold, drought, or fluctuations in temperature can stress the bushes and impact blooming. Provide proper care and protection during extreme weather conditions to minimize stress on the plants.

Age of the Bushes: Young or newly planted Double Knock Out Rose bushes may take some time to establish themselves before they start blooming prolifically. Be patient and continue to provide proper care, and the bushes should begin to bloom more abundantly as they mature.

By addressing these potential issues and providing proper care, you can encourage your Double Knock Out Rose bushes to bloom more profusely and enhance the beauty of your garden.

Winterizing Double Knock Out Rose bushes is essential to protect them from harsh winter conditions and ensure their health and vitality. Here are some steps to winterize Double Knock Out Rose bushes:

Pruning: In late fall or early winter, prune your Double Knock Out Rose bushes to remove any dead, diseased, or damaged branches. Also, consider lightly shaping the bush to promote airflow and reduce the risk of fungal diseases during the winter months. Avoid heavy pruning, as this can stimulate new growth, which is vulnerable to cold damage.

Mulching: Apply a layer of organic mulch, such as shredded bark or compost, around the base of the rose bushes to insulate the soil and protect the roots from freezing temperatures. Apply a layer of mulch several inches thick, extending it a few inches beyond the dripline of the bushes. Mulch helps maintain soil moisture, regulate soil temperature, and protect the roots from temperature fluctuations.

Watering: Proper hydration is crucial for winter survival. Water your Double Knock Out Rose bushes deeply before the ground freezes to ensure they enter the winter months well-hydrated. Avoid watering during periods of freezing temperatures, as this can cause ice to form around the roots and damage them. Resume watering once the ground thaws in early spring.

Protecting Canes: In colder climates or areas prone to harsh winter winds, consider protecting the canes of your rose bushes to prevent winter damage. You can use materials such as burlap or foam rose cones to wrap the canes and shield them from freezing temperatures and windburn. Secure the protective covering around the bushes, ensuring it reaches the ground to trap heat.

Hilling Soil: In regions with extremely cold temperatures, consider hilling soil around the base of the rose bushes to provide additional insulation and protection for the roots. Mound soil or mulch around the base of the bushes, covering the lower portion of the canes.

Monitoring: Throughout the winter months, monitor the condition of your Double Knock Out Rose bushes, especially after severe weather events. Check for signs of frost damage, such as discolored or blackened canes, and prune affected areas as needed once the threat of frost has passed.

By taking these steps to winterize your Double Knock Out Rose bushes, you can help ensure their survival and encourage healthy growth when spring arrives. It's essential to tailor your winterization efforts to the specific climate and conditions in your area to provide the best possible protection for your rose bushes.

Our Process

We have perfected packaging and shipping plants & trees! That is why we DO NOT use any third-party fulfillment like most other online retailers. Your trees go straight from our farm to your door, safely packaged by our team of seasoned professionals. Our process ensures your plants leave our facility and arrive to your door in the best condition possible!