Images Depict Mature Plants
Double Red Knock Out® Rose
Rosa 'Radtko' PP16202 CPBR#3104
Double Red Knock Out® is my “classic red roses, modern effort” pick—full, petal-packed blooms that look romantic and traditional, paired with the tough, dependable habit Knock Out® is famous for. Plant it in full sun, water at the base, and give it one good prune in late winter, and you’ll get months of rich red color in borders or hedges without needing to fuss over it like an old-school rose.
📦 Free shipping on orders over $99.
Delay shipping by leaving us a message at Checkout.
Share:
Double Red Knock Out® Rose for Full Red Blooms, Easy Landscapes, and Season-Long Color
Full, Double Red Blooms With Classic Rose Presence
Double Red Knock Out® Rose gives you that rich, classic red rose look—only fuller. The “double” bloom form means more petals and a more traditional, lush appearance compared with single-flowered landscape roses. In the garden, those blooms read beautifully from the street, and up close they feel romantic and timeless. If you want red roses that look like the real deal but behave like a tough, modern shrub, this one fits the bill.
The red color is bold and confident, making it easy to use as a focal point or as a repeating plant for a strong, cohesive design. It pairs beautifully with evergreen shrubs, ornamental grasses, and white or purple perennials that make the red pop even more. Whether you’re dressing up a foundation bed or adding dependable color along a walkway, Double Red Knock Out® brings a lot of impact without a complicated care routine.
Nonstop Flowering From Spring Through Frost With Minimal Fuss
This rose is built for long-season performance. Double Red Knock Out® blooms from spring through frost in repeated waves, keeping beds and borders colorful for months. It’s also known for the Knock Out® line’s strong disease resistance, which helps foliage stay cleaner and more attractive—especially when the plant is grown in full sun with decent airflow.
Deadheading isn’t required to keep it flowering, which is one of the biggest reasons gardeners love Knock Out® roses. If you want the shrub to look extra tidy, you can remove spent clusters now and then, but it will still keep blooming even if you don’t. With simple base watering, mulch, and a once-a-year pruning refresh, you get consistent red color with an easy, repeatable routine.
A Rounded Shrub That’s Perfect For Borders And Flowering Hedges
Double Red Knock Out® typically matures around 3–4 feet tall and 3–4 feet wide, forming a rounded, well-branched shrub that fits neatly into most landscapes. That medium size is ideal for foundation beds, mixed borders, and mass plantings where you want substantial color without a towering shrub. Repeat it in groups, and you get a bold sweep of red that looks intentional and professionally designed.
It also makes a fantastic flowering hedge. A row of Double Red Knock Out® creates a soft boundary with months of color—more welcoming than a rigid evergreen line and far easier than finicky roses. Because the plant naturally branches well, it fills in nicely when spaced correctly, giving you a dense, bloom-filled hedge that doesn’t require specialized rose knowledge to maintain.
Easy Care Basics That Keep Foliage Clean And Blooms Heavy
For best performance, plant Double Red Knock Out® in full sun. Sun drives stronger bloom cycles and helps foliage dry quickly after rain, supporting cleaner leaves through the season. Water at the base rather than overhead, and you’ll reduce unnecessary moisture on foliage. A mulch ring helps stabilize soil moisture and reduces weeds (keep mulch a few inches away from the base of the plant).
Pruning is straightforward: prune in late winter or early spring to refresh the shrub and encourage vigorous new growth, which is where the best flowers are produced. Remove dead or damaged stems, thin a bit for airflow, and shape it back into a rounded form. With sun, sensible spacing, and one good yearly prune, Double Red Knock Out® reliably delivers a long season of lush red blooms.
| Hardiness Zone: | 5-11 |
|---|---|
| Mature Height: | 3 to 4 feet |
| Mature Width: | 3 to 4 feet |
| Sunlight: | Full sun (best); tolerates light partial sun |
| Bloom Time / Color | Spring to frost; double rich red blooms |
| Soil Condition: | Well-drained soil; improves with compost at planting |
| Water Requirements: | Medium; deep water to establish, then water during dry spells |
| Wildlife Value | Blooms attract bees and beneficial pollinators |
| Resistance | Strong disease resistance; not reliably deer resistant; moderate drought tolerance once established |
| Landscape Uses | Borders, mass plantings, foundation beds, flowering hedge, walkway edging, containers |
How to Care for Double Red Knock Out® Rose
Before you buy Red Double Knock Out Roses, make sure to read about the care instructions that are recommended to keep this plant healthy and thriving.
How should I plant Double Red Knock Out® Rose?
Plant Double Red Knock Out® Rose in full sun in well-drained soil. Dig a hole about twice as wide as the root ball and set the plant so the top of the root ball sits level with the surrounding soil. Backfill with native soil, water deeply to settle, and create a shallow watering ring to guide water into the root zone. Mulch 2–3 inches over the root area to conserve moisture and reduce weeds, keeping mulch a few inches away from the base of the plant. If your soil drains slowly, plant slightly high or improve drainage before planting. A sunny, well-drained start is the quickest path to stronger growth and heavier bloom cycles.
How often should I water Double Red Knock Out® Rose after planting?
Water deeply right after planting, then keep the root zone evenly moist (not soggy) for the first several weeks. A good baseline is a deep soak about once per week, increasing to twice per week during hot weather, sandy soil, or windy conditions. After it’s established, water during extended dry spells and during heavy bloom periods for best performance. Water at the base rather than overhead so foliage stays drier. Deep, less-frequent watering encourages stronger roots and better resilience.
When should I fertilize Double Red Knock Out® Rose?
Fertilize in early spring as new growth begins using a rose fertilizer or balanced slow-release fertilizer. Apply it over the root zone (not against the stems) and water afterward so nutrients move into the soil where feeder roots can absorb them. If you want extra bloom power, feed again after the first major bloom flush. Avoid heavy late-season fertilizing, which can push tender growth when the plant should be slowing down. Consistent, moderate feeding supports better bloom cycles and sturdier branching.
When and how should I prune Double Red Knock Out® Rose?
Prune Double Red Knock Out® Rose in late winter or early spring before active growth begins. Remove dead or damaged stems first, then cut the plant back to a healthy framework to refresh its shape and encourage vigorous new bloom-producing growth. During the season, you can lightly trim straggly growth to keep the shrub tidy, but avoid heavy pruning in extreme heat. Deadheading isn’t required, though a quick cleanup of spent clusters can keep it looking extra polished. A simple yearly prune is usually all it needs to stay dense and bloom-packed.
Additional Information
History and introduction of Knockout Roses:
When rosarian William Radler was a teenager, he resolved to breed a hardy rose that was beautiful, bloomed all season, was disease resistant, and maintained an attractive shrub-like habit. He remains committed to breeding the "high-maintenance" issues out of his roses. He succeeded with his first introduction, Knock Out™, the award-winning shrub rose that mail-order catalogs call "perhaps the best-ever landscape rose for four-season interest." Mr. Radler germinated the first Knock Out seed in his basement during the winter of 1988–89, and that spring he planted the small shrub outside in his garden. The following 11 years were spent overseeing bud grafting, testing, and production of more stock. The rose was offered to the All America Rose Selections committee and declared a winner in 1997. Knock Out became available to the public with 250,000 plants in production. And a star was born. In 1992 a well known company known as Star Roses & Plants near Philadelphia signed a contract with Radler to begin testing on his new rose, a process which took eight years. With testing complete, the company filed for a patent and named the new, easy-care rose Knockout. Sales began in the year 2000.
