By Jennifer Poindexter
Are you looking for a simple yet gorgeous way to landscape your home?
Knockout rose bushes could be the solution. Don’t curl your nose up just yet because knockout rose bushes are nothing like other varieties of roses.
They’re easy, low-maintenance plants that most gardeners can grow without issue. This rose variety was created by a rose breeder named Bill Radler in 1989. Since then its popularity has spread because of the ease and beauty this plant provides for its gardener.
If you’re interested in having a gorgeous pop of color in your garden without working yourself to death, here’s what you should know to begin raising knockout rose bushes:
Growing Conditions for Knockout Rose Bushes
If you’re looking for a “set-it-and-forget-it” rose bush, knockout roses are for you. As long as you purchase a large enough plant, there isn’t much to them.
These rose bushes can grow in partial to full sun. You can plant them inground or in containers. If you choose to grow in a container, take the plant’s size and build into consideration to ensure the planter is large enough.
Knockout rose bushes can grow to become four feet wide and four feet in height. They have a round, compact shape about them.
The biggest necessity is well-draining soil that’s high in nutrients. It’s a good idea to add compost when planting and ensure the rose bush receives plenty of nitrogen.
Knockout rose bushes grow well in planting zones five and higher. If you want to grow them in lower planting zones, place them in containers so you can move them indoors when the temperatures become brutally cold.
Though these rose bushes can’t handle the frigid temperatures of lower planting zones, they’re extremely heat tolerant.
However, if you have higher temperatures in your planting zone, plant the bush where it will receive more shade than sunlight.
By providing the right nutrients and well-draining soil, knockout roses can grow well in most settings. With proper care, they’ll produce beauty for many years.
How to Plant Knockout Rose Bushes
There are many ways to raise knockout rose bushes on your property. The most common method is to head to the nursery, purchase a plant, and plant it.
If this is the method you’re planning on using, it’s simple. Once the plant has been purchased, pick the ideal grow space.
Knockout rose bushes grow well as landscaping, barriers for your garden, in perennial beds, or in containers.
Be sure the area receives full to partial sunlight and has well-draining soil that’s high in nutrients. It’s also wise to plant the bush in early spring or fall while it’s still dormant.
The plot should be one foot deep. Set the plant into the hole, ensure plenty of compost has been worked into the soil, cover the roots tightly with dirt, and water.
Make sure the ground around the rose bush stays moist for the first month after planting. This will help the bush become established.
The next grow method is to start knockout rose bushes from seed. You can harvest them from rose hips on another knockout rose bush.
Once you have seeds, you must stratify them. Knockout roses have an extra phase to sprouting. They require stratification to wake them up.
Cold stratifying seeds means they’re placed in a damp paper towel. The paper towel is placed inside a plastic sandwich bag. The bag is then placed in the refrigerator for two months.
Ensure the bag has proper airflow to avoid the seeds becoming moldy due to trapped moisture. When the stratification process has ended, it’s time to start the seeds.
Place them in a grow tray filled with quality soil. Be sure to spritz the seeds with water to ensure the soil never dries out.
Spraying with water is a good way to make sure the seeds don’t become waterlogged. Provide adequate heat and light as well.
The seeds take approximately six weeks to germinate. When the plants reach three inches in height, they’re ready to be placed in a container or permanent outdoor setting.
Our final method for planting knockout rose bushes is via cutting. Look for a stem on an established knockout rose bush where a rose hip is forming.
Cut eight inches below the rose hip, at an angle, using a sharp set of shears or scissors. This will give you enough of a stem to work with when rooting the cutting.
Remove the leaves from the bottom portion of the cutting and dip the stem into rooting hormone. Place the cutting in a container with nutrient-dense soil that’s also well-draining.
Be mindful not to place the container in direct sunlight. Water the cutting every other day ensuring the soil stays moist without becoming soggy.
Allow the cutting to grow in the container for one year before transplanting to a permanent in ground location unless the knockout rose will be grown in a container garden.
Caring for Knockout Rose Bushes
The knockout rose bush requires minimal care. The biggest maintenance task is pruning. It’s important to prune the bushes in early spring while still dormant.
If you live in a warmer climate, prune the bush to where it’s approximately one foot in height. If you live in cooler climates, prune the bush back to only six inches in height.
When pruning, begin by removing any dead parts of the plant. Once these parts are removed, begin shaping the bush and removing any interior parts of the plant which are no longer productive.
Once these pieces have been removed and shaped, look at the healthy parts of the plant still remaining. Trim the shoots back to about half of their original length.
The reason for cutting the bushes back so much further in colder climates is because the cold temperatures can damage the bush.
If you live in a colder climate, it’s important to make sure you insulate your knockout rose bushes over winter. You can cover them in mulch or straw.
Once the cold temperatures have passed, remove the insulation. You’ll notice any of the exposed parts may have become damaged due to frost and freezing temperatures.
It’s better to prune the plant heavily and allow regrowth than nursing a damaged plant all grow season.
When the pruning is over, be sure to mulch around your rose bushes to help maintain moisture. You should water your rose bushes heavily one time per week to make sure they receive one inch of water each week.
It’s vital to note that knockout rose bushes aren’t drought tolerant, so watering them adequately is a large part of caring for them properly.
Fertilize your knockout rose bushes one time per month during the blooming seasons. Use a fertilize meant for rose bushes.
As long as properly fed, knockout rose bushes should bloom every five to six weeks from spring through fall.
Other than these few minor tasks, knockout rose bushes handle themselves well during the grow season. There’s no deadheading of blooms because they push each other out of the way naturally.
If you can prune one time per year, fertilize one time per month, and ensure each bush receives one inch of water per week, your knockout rose bushes should produce beautifully.
Garden Pests and Diseases for Knockout Rose Bushes
Most roses are prone to diseases and pests. This is why many gardeners gave up on them prior to the creation of the knockout rose bush.
Thankfully, the knockout rose bush isn’t prone to many diseases or pests. The largest threats to these plants are rose rosette disease and Japanese beetles.
The rose rosette disease is actually a virus transmitted to the plants by a mite. Unfortunately, once your knockouts have contracted this disease, there is no cure.
It’s a slow-traveling disease, so if you catch it in time you may be able to remove the damaged part of the plant. You’ll notice the disease because it causes your bush to produce deformed blooms and foliage.
If the disease has progressed, your safest bet is to dig the plant out of the ground and destroy it. Don’t compost an infected plant because it could spread disease throughout your compost pile and make it unusable.
Japanese beetles are another threat to rose bushes. You can treat your plants with diatomaceous earth, insecticides, or traps to remove the beetles from your rose bushes. These beetles are easy to spot and manage to devour foliage quickly.
How to Harvest Knockout Rose Bushes
Most people don’t harvest knockout rose bushes because it’s a bush and doesn’t produce long-stem roses.
However, if you would like to harvest roses from this bush, use sharp scissors or shears to cut the blooms away.
You may be able to cut low enough to give yourself a shorter stem for a small bouquet. Again, most people use the knockout rose bush as gorgeous landscape and a means to provide color in otherwise drab areas.
I have grown knockout rose bushes for years, even before I figured out how to garden, because they are such an easy plant to care for.
Yet, they produce vibrant colors and are a great way to ensure beauty is sprouting all around you. If you need a low-maintenance pick-me-up, a knockout rose bush could be just what your landscaping is missing.