Knock Out Rose

Rosa 'Radrazz'

flower

The Knock Out rose (Rosa 'Radrazz'), introduced in 2000, revolutionized rose growing by being almost foolproof. It is a rounded, bushy shrub rose, typically 3 to 4 ft, that produces flushes of cherry-red, lightly scented single flowers continuously from spring until frost. Crucially, it is self-cleaning (it drops spent blooms and reblooms without deadheading) and was bred for outstanding resistance to black spot and other diseases that plague traditional roses, so it needs no spraying. Cold hardy to about zone 5 and extremely heat- and drought-tolerant once established, it gives the look of a rose garden with a fraction of the fuss.

✅ Plant alongside

Good neighbors that attract beneficial insects or deter pests

• Walker's Low Catmint — Its airy lavender-blue haze sets off the red roses and draws bees, and it shares the sunny, well-drained site
• May Night Salvia — Violet spikes contrast the red blooms and flower on a similar long schedule
• English Lavender — Fragrant, drought-tolerant companion that thrives in the same full sun and is said to help repel aphids

🛡️ Pest & disease prevention

Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide

• Rose rosette disease →

  The most serious threat to Knock Out roses - an incurable mite-spread virus causing witches-broom, excessive thorns, and distorted red growth; there is no cure, so remove and destroy infected plants promptly and avoid crowding

• Japanese beetles →

  Skeletonize leaves and chew blooms in summer - hand-pick into soapy water in the cool morning and avoid pheromone traps that attract more

• Aphids →

  Cluster on new growth and buds - hose them off and rely on ladybugs and lacewings

• Black spot →

  Knock Out is highly resistant, but in wet climates still water at the base, give airflow, and clean up fallen leaves

🌸 Blooms & cutting

Knock Out roses are bred for landscape color rather than long-stemmed cutting, but the flushes of bloom make cheerful short-stemmed posies - cut in the cool morning just as buds open, into clean water. The big advantage is that no deadheading is required: the shrub is self-cleaning and reblooms on its own. The one pruning task that matters is the hard cut-back in late winter, which rejuvenates the plant and fuels the season of bloom. Wear gloves, as the canes have thorns.

🥗 Nutrition & benefits

Unlike packed double roses, the more open single-to-semi-double Knock Out blooms give bees reasonable access to pollen, so it has modest pollinator value alongside its main role as a long-blooming ornamental shrub. It produces few hips because it keeps reblooming rather than setting seed. Its real contribution is months of dependable color with no spraying, making rose-like beauty accessible to beginning gardeners.