
Source: Wikimedia Commons
Revolutionary landscape rose, AARS winner 2000. Cherry-red semi-double blooms non-stop from spring to frost. Exceptional disease resistance, virtually immune to black spot. The definitive spray-free rose.
Bred by William Radler (USA) and an AARS winner in 2000, 'Knock Out' is a revolutionary landscape rose that fundamentally changed expectations for low-maintenance roses. Cherry-red semi-double blooms appear continuously from spring until frost without the need for deadheading — the plant drops its own spent flowers in a self-cleaning habit unique among roses. Resistance to black spot is exceptional; the plant thrives with essentially no chemical spraying even in high-disease-pressure climates. Tolerant of both heat and cold, it has achieved extraordinary adoption across diverse climate zones. At 0.9–1.2m, it is compact enough for most garden situations and requires only a single spring shearing to one-third of its height for annual maintenance. It is widely credited with bringing rose gardening to a new audience of low-maintenance gardeners.
Origin
USA
Lifespan
15-25 years
Size
0.9-1.2m
Temperature
-15〜35℃
−
Full sun. Tolerates both heat and cold
Simply shear 1/3 in spring. Self-cleaning, no deadheading needed
Virtually immune to black spot. Resistant to powdery mildew too
Almost no fragrance. Simple flower form compensated by sheer quantity
Beginner. This is a beginner-friendly species. No special equipment or experience is required, and it can be kept successfully with basic care setup.
The ideal temperature for Knock Out is -15〜35℃. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Knock Out is 15-25 years. With proper care and nutrition, they can live a long and healthy life.
Knock Out typically reaches 0.9-1.2m as an adult. Size may vary depending on care conditions and individual genetics.
Knock Out feeds on: −. Aim for a balanced diet with appropriate feeding frequency.
The price of Knock Out varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
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