Red Double Knock Out Rose

Light Needs

Full Sun

(6+ Hours Direct Sun)

Mature Height

4-5 Feet

Mature Spread

4-5 Feet

Growing Zones

5 to 11

Red Double Knock Out Rose delivers classic-looking double flowers with the easy repeat bloom that made Knock Out® roses famous. The cherry red blooms continue from spring into frost, with 18 to 24 petals and a sweet, fruity scent. The bushy shrub matures about 3 to 4 feet tall and wide, giving beds, borders, and containers a full but tidy rose display. Our landscaper uses Rosa 'Radtko' when a customer wants red roses for months but needs strong disease resistance and simple upkeep.

This Will Radler rose came from the same cross that produced the original Knock Out® Rose. Red Double Knock Out Rose has deep purplish green foliage, abundant flowering, and excellent resistance to black spot, rust, and mildew. It is slightly more winter hardy than the original Knock Out® and earned major recognition, including the 2004 Australian Gold Medal and 2019 American Rose Trials for Sustainability Master Rose award. Plant it as a flowering hedge, foundation shrub, specimen, container rose, mass planting, or colorful anchor in a sunny mixed border.

Red Double Knock Out Rose Care

Plant Red Double Knock Out Rose in full sun for the strongest bloom production, ideally with 6 or more hours of direct light per day. It grows best in fertile, well-drained soil that stays moderately moist during active growth. Slightly acidic to neutral soil is preferred, and compost should be mixed into poor soil before planting.

Water deeply after planting, and keep the soil consistently moist while roots establish. Established plants tolerate short dry spells, but regular deep watering during hot weather supports heavier flowering. Fertilize in early spring with a rose fertilizer, then repeat after bloom cycles according to the product label. Mulch 2 inches deep around the root zone to conserve moisture and limit soil splash on the leaves.

Prune Red Double Knock Out Rose in early spring when new buds begin to swell. Cut out dead, weak, or crossing stems. Once it is established, reduce the shrub to about 12 to 18 inches tall for a fresh season of branching. Deadheading is not required, although light shaping after a major bloom cycle can keep hedges and containers tidy.

Red Double Knock Out Rose Spacing

Space Red Double Knock Out Rose 3 to 4 feet apart for hedges, mass plantings, and foundation groupings. Give individual shrubs 4 feet of room so air can move through the foliage and the plant can keep its rounded habit. For containers, use a sturdy pot at least 18 inches wide with drainage holes, and fill with a rich high-quality potting mix.

In sunny beds, Red Double Knock Out Rose works well with beardtongue and blanket flowers, since they share a preference for bright light and drained soil and add different flower shapes near the rose canopy. For a shrub layer, plant spirea or juniper bushes nearby to add structure below or behind the red blooms. In patio containers, use purslane or calibrachoa along the rim for heat-tolerant seasonal color that can handle the same sunny exposure.

Red Double Knock Out Rose Information

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