The petals are a uniform snow-white shade with a delicate silky sheen. - landscape shrub rose - very faint, barely perceptible scented rose - fresh character
– Long-lasting snow-white flowers in masses.
– Compact, bushy habit ideal for borders.
– Excellent disease resistance in most climates.
– Very low maintenance, self-cleaning blooms.
– Outstanding heat and drought tolerance for urban sites.
– Special feature: Decorated with major awards, including Rose Hills Gold Medal and A.R.T.S.® Master Rose.
Sophisticated flower colours – Natural plant form
pharmaROSA® ORIGINAL 2-litre own-root potted rose
22,90 £
Unfortunately, we are currently unable to ship to the United Kingdom; we only deliver to countries within the European Union. For more information, please contact us!
3.5(4958)
WHITE KNOCK OUT® – white landscape shrub rose – Radler
Effortless and reassuringly tough, WHITE KNOCK OUT® is an easy-care white shrub rose for busy gardens that need dependable structure and long seasons of repeat flowering. Its compact, naturally bushy habit stays neat with only light annual pruning, while the dense, dark green foliage sets off the pure white blooms in striking contrast. Bred for strong disease resistance, it copes well with exposed British sites and wetter spells, even where coastal winds and heavy weather demand a reliable, low-input plant. As an own-root shrub, it gradually builds a robust framework and root system for long-term longevity in your borders. Give it a straightforward planting, basic watering in dry periods and let it develop from first-year rooting to fuller second-year shoots and, by the third season, a mature display of steady performance.
White Knock Out® flowers in the late bloom phase
Usage options
Target area
Reasoning
Front garden focal shrub
The compact, bushy habit and clean white flowers provide an immediate sense of order and brightness near the front door without demanding complex pruning or spraying routines, ideal for tidy but time-pressed homeowners.
Low, easy-care hedge
Planted at the recommended hedge spacing, this variety forms a dense, dark green line that flowers repeatedly, needing only a light annual trim to keep shape, suiting those wanting definition without intensive clipping gardeners.
Small mixed border in family gardens
Its natural compactness and strong disease resistance allow it to sit among perennials and grasses without dominating, providing long-lasting white accents that blend into cottage-style or informal planting for relaxed but style-aware beginners.
Urban and paved-front settings
With recognised heat and drought tolerance and low maintenance needs, it performs well in town gardens, driveways and paved-front plots where reflected heat and irregular watering can challenge fussier roses, reassuring busy city residents.
Weather-exposed sites and coastal edges
The sturdy shrub framework and high disease resistance help it stand up to wind and rain in more exposed gardens, maintaining a presentable, flowering outline even when conditions are changeable, appealing to practical coastal owners.
Feature plant in larger containers
In a 40–50 litre or larger pot, its bushy, self-cleaning habit offers a long season of tidy white bloom with little deadheading, a good option for patios and terraces where straightforward, reliable performers are valued by container enthusiasts.
Low-maintenance mass planting
At bedding or landscape spacing it quickly knits into a continuous, weed-suppressing canopy, providing repeating waves of white flower with minimal feeding and pruning, making it ideal for those wanting generous effect from simple care planters.
Long-term backbone shrub in small beds
As an own-root rose it develops a stable, regenerating framework over the years, maintaining shape and flowering even after harder pruning if needed, giving confidence to those planning enduring, structural rose areas for family gardens.
Styling ideas
Cottage Mix – Combine with soft pink roses, nepeta and lavender for a gentle, traditional front-border feel – ideal for lovers of classic cottage style.
Monochrome Calm – Pair WHITE KNOCK OUT® with white gaura and silver foliage such as stachys to create a serene, easy-care white-and-silver scheme – suited to minimalist gardeners.
Grass Partner – Underplant with Carex flacca ‘Blue Zinger’ and low sedges so the dark foliage and white blooms rise from a cool, textural base – appealing to design-conscious small-garden owners.
Urban Patio – Grow in a large 50-litre container with trailing thyme and heuchera for a compact, long-flowering feature by seating areas – perfect for balcony and courtyard gardeners.
Family-Friendly Border – Mix with echinacea, hardy geraniums and dwarf ornamental grasses to create a colourful, low-fuss strip along paths – attractive to busy family households.
Technical cultivar profile
Parameter
Data
Name and registration
Modern shrub (landscape) rose; registered as RADwhite, marketed as WHITE KNOCK OUT®, part of the KNOCK OUT® collection, also known at shows as ‘White Out’.
Origin and breeding
Bred by William J. Radler in the USA from ‘RADmom’ × ‘RADsweet’; introduced by Star Roses and Plants in 2009 in the US and by Meilland International in Europe.
Awards and recognition
Gold Medal at Rose Hills International Rose Trials 2011, Merit Certificate at Bagatelle 2017, WUCOLS Blue Ribbon water-saving rating 2017–2019, A.R.T.S. Master Rose 2021.
Growth and structural characteristics
Compact, bushy shrub reaching about 90–120 cm in height and spread, with dense, matt, very dark green foliage and moderate prickles, naturally forming a neat, well-branched outline.
Flower morphology
Medium clusters of single, flat blooms with around 5–12 petals, typically 4–7 cm across; self-cleaning flowers mostly drop once spent, helping the plant remain tidy between flushes.
Colour data and phenology
Pure white blooms with a silky, slightly pearlescent sheen, RHS 155C–155D, holding colour well with minimal fading; repeated flowering through the season, including a notably abundant second flush.
Fragrance and aroma
Flowers carry a very light, fresh character fragrance that is barely perceptible in the garden, intended more for visual than scented effect, suiting those sensitive to strong perfumes.
Hip characteristics
Occasional small spherical hips around 5–7 mm across, coloured orange-red; produced sporadically and may add a modest decorative note in late season without heavy fruiting.
Resistance and winter hardiness
Rated H7 with USDA hardiness around zone 4b, tolerating approximately −32 to −29 °C; strong resistance to black spot, powdery mildew and rust, suitable for low-spray gardens.
Horticultural recommendations
Best at 65–75 cm spacing for hedges or beds; suits borders, low hedges and mass planting; low feeding needs and minimal pruning, preferring full sun but tolerating partial shade.
WHITE KNOCK OUT® offers reliable flowering, compact shrub structure and strong disease resistance on a durable own-root framework, making it a sound choice if you seek a long-lived, low-effort white rose.
Detailed product attributes
Product Identification Data
Product Name:
WHITE KNOCK OUT® – white landscape shrub rose - Radler
Product Type:
pharmaROSA® ORIGINAL - 2-litre own-root potted rose
Meaning of Cultivar Name:
The name refers to the white-flowered member of the "Knock Out" series; "Knock Out" denotes a knockout or victory and "White" indicates the white colour.
Cultivar Synonym:
White Out™; Knock Out White®; Rosa ‘White Out’
Competition and Show Awards:
Rose Hills International Rose Trials – Gold Medal (2011); Bagatelle (Paris) – Merit Certificate (2017); WUCOLS Blue Ribbon™ (outstanding water-conservation performance) (2017–2019); A.R.T.S.® Master Rose designation (2021)
Pollinator Attraction:
Its simple (single), 5–12-petalled flowers attract pollinators only to a limited extent, as the single flower form and relatively inaccessible stamens reduce their attractiveness.
Our product is a rose grown with pharmaROSA®’s unique cultivation technology!
2-litre, own-root, potted rose.
With a shoot system appropriate to the season.
With a root system that thoroughly permeates the growing medium.
Quality compliant with the requirements of the E.N.A. (European Nurserystock Association).
Supplied in unique packaging that prevents damage.
Can be planted during frost-free periods.
True-to-variety rose bush with a unique identifier.
The pharmaROSA® own-root potted rose is a well-rooted plant that supports reliable establishment when planted and cared for properly, so it can be planted whenever the soil is not frozen.
Crop overview: several varieties and growth stages in a short crop section.Shoot system: intensive growth of fresh basal shoots on a young plant.Root system: demonstration of a vigorous root system permeating the growing medium, by removing the pot.Balance: mature plant with root system and shoots in harmony with each other.
Information about the videos
The video series is not a “seasonal showcase”; it illustrates the essence of pharmaROSA® own-root cultivation in a tangible way: how the plant is built up, what the root system is like and how the shoot system regenerates. The recordings were therefore made at different times and with plants at various stages of development, so mixed foliage levels and differing stages of growth may appear in the videos. They are not a ‘sample’ of the batch dispatched, but a visual explanation of how the technology works. The current condition of the rose available to order — typical for the given period and similar to what you can expect to receive in the parcel — is shown in the upper part of the product page.
Pages for private customers Garden roses for the family garden, with minimal care → ORIGINAL® Premium garden roses – instant impact, a truly showpiece garden → EXTRA® Pages for professionals and private customers Roses for public spaces – large areas, sustainable maintenance → NATURAL® Roses for projects – hedge and row planting, fast implementation → RAPID® For professional partners only Production – propagation material for garden roses, wholesale → NEONATAL®
Company details
PharmaRosa Ltd. Company registration number: 01-09-717479 VAT number: 13075314-2-43 Plant health registration no.: HU130721 Bank account (IBAN): HU85117631891388688400000000 BIC (SWIFT): OTPVHUHB Bank name: OTP Bank Nyrt.
