In the last 30 years Knock Out® roses have gone from the Milwaukee basement of amateur rose breeder William Radler to be a household name for disease-resistant, reliable, easy-care rose bushes. Now we are thrilled to have the first miniature rose in the collection. A superb bushy plant 18 inches tall, the cup-shaped bright-red flowers may be small, but they pack a knock-out punch of color that will bring your garden to life. We loved it so much we decided to go to the next round, and we had our growers raise them on a short but sturdy stem, creating the very first Petite Knock Out® Rose Tree. That’s right – the stem turns this into a plant that stands around 4 feet tall, lifting those charming pure-red flowers closer, where they can be appreciated much more fully, without getting down on your knees. Or, you can use it in a tub or planter, and have it almost at eye-level, while beneath it flowers and trailing plants tumble out, creating the perfect summer arrangement. However you grow it, you’ll love it.

Growing the Petite Knock Out® Rose Tree

Size and Appearance

The Petite Knock Out® Rose Tree is a deciduous flowering shrub that is a bushy rose raised on a strong trunk. In a single season the bushy upper part grows into a rounded plant about 18 inches tall and wide. The stem thickens with age, but of course never grows taller. From spring to fall it is covered in dense foliage that is always healthy and fresh. The leaves are about 4½ inches long, divided into 5 or 7 leaflets, arranged in pairs along a central stem, with one leaflet at the end. This abundance of small leaflets creates a beautiful bushy look, and each glossy oval leaflet is dark green, with fine serrations around the edge.

In spring an abundance of new stems sprouts out, each one ending in a cluster of up to 6 individual flower buds on short stems. These continue to be produced more or less continuously, from spring, through summer and well into fall. These charming pointed buds soon open into bowl-shaped flowers 1½ inches across. These have 9 to 12 petals surrounding a center of golden stamens and tiny twisted petals, creating a beautiful effect, and they are a brilliant and clear rich ruby red. It’s a gorgeous pure color, free of either orange or purple tones. The flowers eventually fade, and the petals drop off cleanly, before they turn brown and unsightly. Old flower clusters quickly disappear among the new growth, or they can be dead-headed. Blooming is continuous through the seasons, making this one bush a colorful feature that keeps on giving and giving from late spring through into fall.

Using the Petite Knock Out® Rose Tree in Your Garden

This bush is perfect as an accent in any bed, especially smaller ones, along paths, by a gate or door, or by a set of steps.. Grow it alone, as a pair or as a row – all these give different effects and impacts. It is also an excellent plant for growing in pots and planter boxes, giving height without excessive width, and tons and tons of color. Place these on a terrace, patio or balcony, and grow alone or with annual flowers, trailing ivies or low-growing perennials underneath it – a complete flower display in one container.

Hardiness

The Petite Knock Out Rose Tree is incredibly hardy and adaptable to a huge range of climates. With protection for the stem it can be grown in zone 4, and it grows readily in zones 5 to 10. Plants in planter boxes will overwinter outdoors from zone 6. In cooler zones protection is needed.

Sun Exposure and Soil Conditions

For good results and continuous blooming, plant the Petite Knock Out Rose Tree in full sun. Shade of more than an hour or two a day will significantly reduce flowering. The ideal soil is rich and fertile, well-drained but normally moist. It grows well in clay and heavy soils. Enrich the ground with plenty of organic material when planting, and use more as mulch each spring. For pots and planters, mix one-part garden soil with two-parts of potting soil.

Maintenance and Pruning

Feed plants regularly, using liquid rose fertilizers for plants in containers. Slow-release forms also work well. The Petite Knock Out Rose Tree is incredibly resistant to common rose diseases, especially to Black Spot, but with broad-spectrum resistance to most problems. Its vigorous growth means pests are rarely problems, and they can be controlled safely with soap sprays or Neem Oil spray.

Prune once a year, in early spring, just as the new buds are swelling. Remove any weak or broken stems from within the bushy upper part, and shorten back the remaining stems to a strong outward-facing bud. Remove any growth on the trunk or from the roots as soon as it is seen. Never cut back the upper part below the point where it connects to the stem. Dead-head spent flower heads as you wish – it isn’t essential – removing them back to the first full-sized leaf. See this blog for details on winter protection in colder areas.

History and Origin of the Petite Knock Out® Rose Tree

The Knock Out range of roses has come a long way since the amateur rose-breeder Will Radner grew the first seedling. Since that first rose Will Radner created in his basement in Milwaukee he has developed a whole range of plants, but for the Petite Knock Out® Rose Tree the brand owners, Star® Roses and Plants, turned to one of the world’s most famous rose-breeding families. Alain Meilland is the present head of the French family that gave the world the ‘Peace’ Rose after WWII. He created the rose officially called `Meibenbino` after multiple crosses. He took pollen from a seedling of a cross that began with his own pink rose, Baby Romantica® (`Meipaonia`) and used it on Will Radner’s rose-red Double Knock Out® (`Radtko`). Among the seedlings that grew he found one that was exactly what he wanted – a miniature rose with bold red flowers. At first it was released by the Meilland nursery as ZEPETI®, but once it was patented in the US in 2019 it was released here as Petite Knock Out®.

Buying the Petite Knock Out® Rose Tree at the Tree Center

We love this rose – it’s another great addition to the range – and we are thrilled with how it looks turned into a tree rose. It’s charming and everyone loves it. The Petite Knock Out® Rose Tree will add a whole new dimension to your garden display, but order now, because we simply can’t get enough of these plants to have any chance of making everyone happy.