The Petite Knock Out ® Rose is an easy-to-grow shrub rose bush that can be added to your indoor plant collection now — then brought outside to your garden come spring, when temps are consistently above 60 degrees Fahrenheit. With ample light and water, your petite rose bush will bloom vibrant red flowers early spring through late summer. Learn more about caring for your Petite Knock Out ® Rose below.
I. Appearance and Characteristics
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.
II. How to Grow and Care
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.
Sunlight
Thrives in bright direct sun for 6-8 hours per day, so choose a sunny spot in your home! Indoors, flowers will last for 2-3 weeks.
When flowers begin to fade or plants start to look sad, you can take your plant outside and keep in the container or plant into the ground, as long as temps are warm enough. If it’s too cold outside right now, we recommend waiting it out indoors for warmer temps and keeping your rose bush in a sunny spot where you can water it regularly.
Your rose bush will go semi-dormant from early fall through winter, which is typical of most blooming plants.
Watering
Water every 2-3 days, allowing soil to dry out at least two inches down between waterings. Expect to water more often in brighter light and less often in lower light.
Soil
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.
Planting Instructions
- Choose a sunny space outside. Your rose bush requires a minimum of 6-8 hours of sunlight each day.
- Dig a hole slightly larger than the container your rose bush is in. Use your shovel to loosen up the soil at the bottom of the hole you’ve dug.
- Remove your rose bush from its container and loosen its roots.
- Place the bush in the hole and make sure that the base of the plant is in line with the soil.
- Break up potting soil into looser pieces and add it around the plant.
- Water the rose bush around the base of the plant.
- Continue to check on the plant and water it as needed.
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.
Pests and Diseases
If powdery mildew becomes an issue from overcast days with high humidity, and mild temperatures there are a couple of options to help correct the problem. An application of horticultural oil should smother the spores and reduce spread of the problem. It is best to try this as soon as possible upon visible symptoms. An early sign of powdery mildew is a slight curling upwards of the foliage.
Another option is to try trimming back the worst affected areas and wait for new, clean growth to flush out then apply the oil spray as a preventative.
To help mitigate any foliar, stem or flower diseases, it is advisable that you water at the base of the plant and not over the tops i.e. overhead watering because this is an invitation for fungal diseases to develop. When watering, it is recommended to provide slow, deep watering instead of frequent, shallow waterings.
III. Uses and Benefits
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.
