Knockout roses are a fantastic, sturdy variety of rose developed by William Radler. Since 2000, when knockout roses became commercially available, they have bloomed in popularity.
Serving as an attractive, low maintenance shrub, they often adorn borders, hedge lines, and fences in yards across America.
Knockout roses are most often grown in the ground, but container planting is well-suited for these colorful roses. But it does take a bit more care, especially during colder months in USDA hardiness zones above 5.
Knockout Rose Varieties
If you’re planning growing Knock Out Rose plants in containers, there’s no limit to the Knockout varieties from which to choose. They’re all low-maintenance and about the same size.
The primary difference is in the color and number of blossoms you’ll enjoy:
- Sunny Yellow Knockout – vibrant yellow blossoms
- Blushing Knockout – pale pink blossoms
- Double Flowered Knockout – two red blooms per stem instead of one
- Pink Double Knockout Rose – Double Pink blooms
- Rainbow Knockout – Pink on the edges, yellow in the center
Growing Knockout Roses In Containers
The most significant difference between growing knockout rose bushes in the ground versus in a container has to do with water needs and protection from freezing weather.
Knockout roses are water-loving plants that thrive in rich, well-drained soil.
Water knockout roses in containers at least twice a week, even more often during windy or hot spells. In those cases, you may need to water your knockout roses daily.
Protecting Your Container Roses From The Cold
Knockout roses are winter hardy only in USDA hardiness zones five and above.
In other areas, move knockout roses to a building such as a garage, a shed, or a greenhouse to protect them from freezing temperatures.
For further protection, wrap knockout roses in burlap.
Details: Winter Care of Knockout Roses
Light Needs For Knockout Roses In Containers
Whether planted in the ground or containers, all knockout roses need at least six hours of sunlight per day.
These plants are not well suited for indoor living. They may survive in shaded areas, but will not bloom as well as they should.
Feeding Your Knockout Roses
Knockout roses love nutrient-rich soil. Feed them a diluted water-soluble rose fertilizer every two or three weeks throughout the growing season to keep them healthy.
How To Plant Knockout Roses In Containers
To plant your knockout roses in containers, ensure the container size is one size larger than the nursery pot. You can do this any time of year, but spring, before the first bloom, is best.
Aim for at least a 10 to 15-gallon pot or box. Choose soil that provides good drainage.
You may buy a potting mix designed specifically for roses. Or you may choose to mix half potting soil with half organic compost.
- Fill the bottom of your pot with a couple of inches of gravel.
- Pour in your rich well draining soil mixture.
- Gently disturb the roots on the bottom of your root ball.
- Place the root ball in the planting hole of the new pot.
- Surround the root ball with soil.
- Fill your pot up to 1″ to 1 ½ ” inches below the rim.
- Do not cover the crown (the point where the plant meets the root ball).
- Give it a good dose of water.
To help retain moisture and keep temperatures comfortable, lay down a top layer of tree bark mulch or shredded leaves.
Grooming And Maintenance
Knockout roses need minimal care and grooming while growing in their containers. The blooms will fall off on their own when they’ve reached the end of their cycle. But, you can still prune them if you choose.
You may also choose to shape your roses. Remove crowded stems to allow ample light and air to reach all parts of the plant.
You may also prune Knockout plants down to 12″ inches during its dormant period in the winter. When cutting, cut at a slant that points inward toward the center of the plant.
Keeping Pests Away From Knockout Roses
Knockout roses are not susceptible to many fungal diseases like traditional roses are. Overall Knock Out roses are disease resistant. They are susceptible to pests, though, such as aphids and Japanese beetles.
Learn about Diseases of Knock Out Roses
Treat Japanese Beetles on Knockout roses with insecticide or traps. Place the traps a proper distance from the knockout rose.
If there aren’t many, you can handpick the beetles and drop them in a container of water and dish soap.
Aphids cause issues for many plants, roses included. Luckily nature takes care of most of them via aphid eating predator insects and parasites.
If they are a particular problem for your knockout rose, remove the most infected stems.
Rose slugs chew on plant leaves leaving their mark where they have chewed. The rose slugs put holes in the leaves but do not harm the plant healthwise.
Knockout Roses – Bottom Line For Container Planting
Knockout Roses are easy to grow in containers as long as they receive adequate water and protection from the cold.
Plant them in nutrient-rich, well-draining soil, and place them in an area that receives at least six hours of direct sunlight.
Bring them into a garage, shed, or other building during months where temperatures hit freezing.