Knock Out Rose
Rosa 'Radrazz' (Knock Out Series) — trademarked by Star Roses and Plants
📖 About this plant
The Knock Out Rose revolutionized rose gardening when it was introduced in 2000, becoming the best-selling rose variety in North America. Bred specifically for disease resistance, cold hardiness, heat tolerance, and non-stop flowering, it requires minimal care compared to traditional roses. It produces clusters of vibrant cherry-red, pink, yellow, or coral flowers from spring through hard frost with almost no deadheading required. The ultimate ‘plant it and forget it’ landscape rose.
🧑🌾 Care requirements
Full sun (6+ hrs)
Every 1-2 weeks
Moderate (40-60%)
5-35°C
Adaptable to most well-draining soils (pH 5.5-7.0); tolerant of clay, sandy, and poor soils; mulch well for best performance
Balanced rose fertilizer (10-10-10) every 6-8 weeks during growing season; light feeder — avoid excessive fertilizing which produces foliage at the expense of blooms
📋 Plant facts
- 🌍 Origin
- United States — bred by William J. (Bill) Radler in Greenfield, Wisconsin; introduced in 2000 by Star Roses and Plants; winner of the All-America Rose Selections (AARS) award in 2000
- 📏 Max height
- 90-150 cm (3-5 ft); bushy, rounded, dense habit
- 📐 Spread
- 90-150 cm
- 🕰️ Bloom time
- Spring - Fall
- 🎨 Bloom color
- Pink, Red
- 🍃 Foliage color
- Dark Green
- ⏳ Lifespan
- Perennial
- 📈 Growth rate
- Fast
- ☠️ Toxicity
- Non-toxic — bred from Rosa wichuraiana and other species rose parentage. Petals and hips are edible. Thorns are moderate. Generally safe for pets; minimal GI upset risk from leaf ingestion.
- 🌱 Propagation
- Patented and trademarked — propagation by license only; commercially produced from cuttings and tissue culture (own-root plants); softwood cuttings with rooting hormone
🛡️ Health & Safety
Non-toxic — bred from Rosa wichuraiana and other species rose parentage. Petals and hips are edible. Thorns are moderate. Generally safe for pets; minimal GI upset risk from leaf ingestion.
Common issues
- Extremely disease-resistant — black spot and powdery mildew are rare, Japanese beetles are the primary pest, Aphids in spring on new growth, Rose rosette disease (fatal — transmitted by eriophyid mites), Frost damage on new growth in early spring (recovers quickly), Becomes leggy if not pruned hard in early spring (cut back to 30 cm)
💡 Care tips
- Most disease-resistant rose variety available today,Self-cleaning so no deadheading required for continuous bloom,Tolerates heat drought and poor soil conditions,Compact size perfect for borders containers and mass plantings
