WHITE KNOCK OUT® – pharmaROSA® NEONATAL rooted cutting
Uniformity and coverage make WHITE KNOCK OUT® a reliable pharmaROSA® NEONATAL option wherever dense, low-maintenance mass-planting material is required for nursery beds or project-oriented container production. Its compact, bushy structure and very dark green foliage support a uniform, dense, bush-trained finished product in 1.5–2 L pots, with predictable height and spread that suit bed and landscape specifications. The variety’s disease resistance and H7 winter hardiness help underpin long-term project supply in exposed UK sites, while its good heat and drought tolerance supports schemes where summer irrigation may be restricted, offering dependable performance in cooler, wind-exposed regions and harsher public-realm conditions. The self-cleaning habit, repeat flowering and stable, snow-white colour with very good retention reduce in-season maintenance and keep stock visually sale-ready in nursery blocks. As an own-root, tray-grown cutting, it supports predictable development curves towards mass planting: roots consolidating first, then structural shoot build-up, then full ornamental value in the third season, giving nurseries and wholesale partners a stable platform for large-scale project scheduling and contract fulfilment.
Usage options
Finished-product ideas
- Project 2 L white landscape module – Uniform, dense, bush-trained plants in 1.5–2 L pots, built on compact, bushy growth and strong disease resistance, for quick deployment into mass planting schemes – target: landscape contractors via project-focused wholesalers.
- 40–50 L structural park feature – Selected, well-branched individuals stepped up from NEONATAL to large 40–50 L containers, using hardiness and good drought tolerance to create robust white accents in parks – target: municipal and institutional procurement.
- Water-wise urban shrub line – A contract line emphasising WUCOLS-recognised water-conservation performance and low maintenance needs, produced as uniform 1.5–2 L units for cost-efficient, low-input urban projects – target: integrators and framework suppliers.
- White thematic bed series – Consistent snow-white, colour-stable shrubs offered as a repeatable, dense bed unit from own-root cuttings, ensuring homogeneous coverage and predictable repeat flowering – target: show gardens, thematic collections and design practices.
- Collection and reference block stock – Verified-authentic, own-root plants grown in 1.5–2 L pots for use as mother blocks or display alleys, leveraging structural compactness and long-term stability – target: nurseries maintaining cultivar libraries and public collections.
Technical cultivar profile
| Parameter |
Data |
| Name and registration |
Modern shrub (landscape shrub) rose, registered as RADwhite, traded as White Knock Out®, also known as White Out in exhibition use; part of the KNOCK OUT® collection aimed at landscape bedding. |
| Origin and breeding |
Bred by William J. Radler in the United States from cross ‘RADmom’ × ‘RADsweet’; introduced 2009 (USA) with US plant patent PP 20 273, distributed by Star Roses and Plants and Meilland International. |
| Awards and recognition |
Holder of Rose Hills International Rose Trials Gold Medal (2011), Bagatelle Merit Certificate (2017), WUCOLS Blue Ribbon for water-saving performance (2017–2019) and A.R.T.S. Master Rose designation (2021). |
| Growth and structural characteristics |
Compact, bushy, well-branched shrub reaching 90–120 cm in both height and spread, with dense, matt, very dark green foliage; moderately thorny shoots and a habit supporting uniform, low-maintenance beds and hedging. |
| Flower morphology |
Single, flat flowers with 5–12 petals, medium-sized at approximately 1.5–2.75 inches, borne in clusters; repeats well through the season with a notably abundant second flush and good natural self-cleaning of spent blooms. |
| Colour data and phenology |
White blooms with ARS code w and RHS 155C–155D, newly opened flowers pure white with pearlescent sheen; colour long-lasting with very good retention, softening slightly to creamy white with a faint pale green edge before aging. |
| Fragrance and aroma |
Fresh but very faint fragrance, barely perceptible in normal use; single flowers offer only limited pollinator attractiveness due to relatively inaccessible stamens, making it chosen more for visual and structural than ecological impact. |
| Hip characteristics |
Occasional small spherical orange-red hips, 5–7 mm in diameter, may appear after flowering; not produced in large numbers but can add a light ornamental accent in late season without affecting overall landscape performance. |
| Resistance and winter hardiness |
High disease resistance with documented resistance to powdery mildew, black spot and rust; hardiness to approximately –32 to –29 °C, corresponding to RHS H7, Swedish Zone 5 and USDA Zone 4b, supporting use in cold climates. |
| Horticultural recommendations |
Recommended for flowerbeds, borders, low hedges, parks and urban green spaces, particularly in project mass plantings; low maintenance needs with minimal pruning and feeding, ideal as a uniform, dense bush-trained finished product from 1.5–2 L pots. |
WHITE KNOCK OUT® offers compact, uniform growth, strong disease resistance and recognised water-efficient performance on a predictable own-root base, making it a pragmatic option for nurseries and wholesalers interested in discussing volume planning and project timing.
