Rose ‘White Knock Out’

White Knock Out Rose (Rosa 'White Knock Out') is the rose for gardeners who want the flowers without the spray program. It makes a tidy bush about 1.2m tall and 1m wide, repeat flowering in clean single white blooms right through the warm months, and it was bred for disease resistance rather than the show bench. It is also non toxic to cats and dogs, which few flowering shrubs of this size can claim.

Why you'll love it

• It keeps flowering. Rather than one heavy spring flush, it produces waves of bloom from spring to late autumn.
• Bred to resist disease. A landscape rose selected for tough foliage, which means far less black spot and mildew than a traditional hybrid tea.
• Safe around pets. Not toxic to cats or dogs, so it can go beside a lawn where animals run. The thorns are still thorns.
• Good for bees. Open single flowers leave the centre accessible, unlike a packed double bloom, so bees and butterflies actually use them.

Where it works best

Low flowering hedges. Plant 90cm apart for a flowering hedge. At that spacing the bushes meet at about waist height and read as a continuous line of white.

Borders and mass planting. Repeated in groups of three or five it gives a border rhythm all season. Underplant with catmint, salvia or low grasses to hide the bases of the canes.

Pots and feature planting. A 400mm or larger pot with good drainage suits it, and container growing usually holds it nearer 1m. As a feature, place it where white shows against a dark hedge.

Growing White Knock Out rose in Australia

Position and climate. Full sun, with at least six hours of direct light and air movement to keep the leaves dry. It suits subtropical, warm temperate, cool temperate and Mediterranean gardens, and it is frost hardy, so cold southern winters are no obstacle. In the subtropics it behaves closer to evergreen.

Soil. Well drained loam enriched with compost and aged manure before planting. Roses dislike waterlogging, so raise the bed on heavy clay, and keep 75mm of mulch clear of the stems.

Water and feed. Deep soak twice a week through the first summer, then weekly in warm weather. It is drought tolerant once established, though flowering drops away under stress. Feed a complete rose fertiliser in early spring and mid summer.

Pruning. Simple by rose standards. Cut the bush back by about a third in late winter, remove dead or crossing canes, and deadhead through the season to keep the next flush coming.

What to expect when it arrives

This rose is grown here as tube stock, so it arrives as a small own root plant rather than a budded bush on a stem. Own root roses take a season longer to reach full size, but they never throw rootstock suckers, and after a hard frost they reshoot from the base as the same variety. Expect first flowers in the first warm season.

Plants are delivered Australia wide, with delivery from $29.95 and a minimum order of $300 before delivery. Plant into prepared soil and keep the water up through the first summer. Every plant carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• Browse the full rose range
• How to plan a cottage garden in Australia
• See other plants safe for pets
• Compare plants that attract bees and butterflies

Common questions

How far apart do I plant it for a hedge?

Ninety centimetres apart in a single row. The bushes reach about a metre across, so at that spacing they touch and form a continuous flowering line while air still moves between plants.

Is it fragrant?

Only lightly. This variety was bred for flower volume and disease resistance rather than perfume, so if scent is your priority an old garden rose will serve you better.

Do I still need to spray for black spot?

In most gardens, no. The foliage resists black spot and mildew far better than traditional roses, though a humid summer with poor air movement can still bring some spotting. Good spacing and watering at soil level do the rest.