Double Knock Out® Rose
Description
About the Double Knock Out® Rose Plant
Enjoy twice the blooms and classic rose beauty! The Double Knock Out® Rose (Rosa ‘Radtko’) features an abundance of lightly fragrant, cherry red double blooms with twice the number of petals as the original Knock Out® Rose. Its classic rose shape, paired with deep purplish-green foliage, adds a striking, colorful accent to any landscape.
Bred by Will Radler in Milwaukee, Wisconsin, this variety was released in the early 2000s. It quickly gained international recognition, winning an Australian Gold Medal (2004) and earning the Master Rose title in 2019 from the American Rose Trials for Sustainability.
Why Gardeners Love the Double Knock Out® Rose
- Continuous Blooms from late spring until the first frost
- Self-cleaning flowers—no deadheading required
- Excellent disease resistance to black spot and downy mildew
- Low maintenance and hardy, even in tough conditions
- Grows into a compact shrub, 3–4 feet tall and wide
- Works beautifully as a stand-alone specimen or rose hedge
Double Knock Out® Rose Uses
These edible rose petals are as practical as they are beautiful. As long as they’re chemical-free, the petals can be used to:
- Add color to teas, lemonade, or juices
- Infuse into butter, jams, or salads
- Steep for homemade rose water
- Dry for use in potpourri or crafts
And as a cut flower, Double Knock Out® Roses provide an almost endless supply of vibrant blooms for fresh floral arrangements throughout the season.
How to Grow Double Knock Out® Roses
These roses are heat- and drought-tolerant once established and are well-suited for gardeners of all experience levels.
- Sunlight: Full sun (6–8 hours daily)
- Spacing: Plant 3–4 feet apart on center for airflow and best growth
- Size at Maturity: 3–4 feet tall and wide
- Soil: Well-drained soil with moderate moisture
- Pruning: Optional; prune in early spring before buds form
- Container Friendly: Yes—just choose a pot twice the size of the original nursery container and keep it well-watered in full sun
A Rose That Delivers on Beauty and Performance
Whether you’re looking to buy Double Knock Out® Roses as a focal point, hedge, or container plant, this patented variety delivers unmatched flower power with almost no effort.
Order today and enjoy a landscape filled with vibrant red blooms on a rugged, easy-to-grow rose you can count on year after year.
This variety may be protected by USPP #16,202 or other patents and is sold under license from the patent owner.
Survival Guaranteed!
Since 1816, Stark Bro’s has promised to provide customers with the very best fruit trees and plants. It’s just that simple. If your trees or plants do not survive, please let us know within one year of delivery. We will send you a free one-time replacement, with a nominal shipping fee of $9.99. If the item in question is not available, we can issue a one-time credit to your account equaling the original product purchase price or issue you a refund. Read more about our warranty policy.
Characteristics
| Bloom Color | Red |
| Hardiness Zone Range | 5 - 9 |
| Shade/Sun | Full Sun |
| Soil Composition | Loamy |
| Soil Moisture | Well Drained |
| Soil pH Level | 5.5 - 7.0 |
Size & Spacing
Mature Size
Recommended Spacing
Zone Compatibility
Tools & Supplies
Planting & Care
Learn all about how to grow roses in The Growing Guide. An entire section of our website dedicated to your growing success.
Shipping Information
Arrives when it's time to plant
Questions & Answers
Yes you can. I put 3 of my roses in large pots in case the ones that I planted
did not survive. They all lived through one of the coldest winters that we have had
and I found places for those 3 plants this year. The ones in the ground did grow larger but they all grew well.
Your climate is much different than mine. My experience is southern Indiana and is with sandy soils. My plantings are on the south side of my house and they are in full sun. My experience is amazing. You would not think that with the plants that you will receive especially when you compare them to what you would get at a big box store. They will be small but will equal what you get at a big box in one season. I would think they would do well for you in your application as long as you keep them fed, watered and keep them treated with fungicide. These plants are much more economical unless you wait till clearance time at the big box stores. I will get about 3 bloom cycles in my area through the summer. I trim mine back after each bloom cycle to keep them looking good.
It should be fine as long as you give it enough---not too much!---water. Mine are doing great and they got planted in a late summer heat wave last year.
You are right on the edge of the growing zone for Knock Outs. If you are near salt air, that will damage them, but if you can keep them out of hot late-afternoon sun and give them good air circulation, they should do OK.
Hi Michelle,
Yes cut them back to 18”-24” inched November 1st or after freeze, mulch about 8” with leaves. Don’t fertilize
Kevin
Hello!
I planted 18 of these roses last spring. All are thriving this spring with lots of buds. At one year in the ground the shortest is 25 inches the tallest 36 inches. None are quite as wide as they are tall. The growth will depend on quality of soil , moisture, and amount of sun. Mine got some bunny munching last spring and I had to use a hardware cloth wrap for protection. So, they lost some growth due to rabbits.
Everyone that I know that has planted this particular rose, says they are very hardy regardless how you plant them. One guy even sprayed weed killer on his by accident, and they were still ok. Mine seem to prefer the full sun.
They will last years. 9 years at our house so far. You can trim them in the fall the second year planted to eight inches or so. They grow quickly and are winter hardy.
Yes they do. I took a picture to post it but can't do it here. I'll see if I can do a review and put it there.
These plants are propagated by cuttings because they're hybrids.
Customer Reviews
Need some pretty flowers.
I love roses but haven't tried growing them. This one looks promising.
have in yard for years
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