The knock out rose

Roses are some of the most beautiful plants in the world. There are many varieties blooming in different colors and sizes. These plants will bloom from spring until autumn with the correct care. Keeping these plants healthy and blooming does take a bit of time for the gardener. The effort is worth the work as the roses will continue to produce blooms throughout their entire season with the correct care. Knockout roses will produce blooms every five or six weeks from mid-spring to autumn if deadheaded.

Why Deadhead

When a rose fades after it blooms and dies this is called a deadhead bloom. This is common to all plants with flowers; however, roses bloom more than most plants and this happens quite often. Taking these dead blooms off the rose plant will keep the plant neat and looking well kept. Taking off the dead blooms or deadheading a gardener will make it easier for the plant to bloom more often and producer larger roses.

Preparing To Cut

When preparing to cut make sure the shears are sharp. Dull shears will make this job more difficult. It may also damage the plant itself by leaving torn and ragged ends where the cut is made. Make sure heavy gardening gloves are worn. These heavy gloves are used to avoid being scratched by thorns. Leather gloves may also be used for this purpose. If reaching into the plant or above the head it is recommended to wear a heavier shirt to avoid scratches to the arms.

Cleaning The Shears

Mix one part bleach to ten parts water in a bucket to make a sanitizing wash for the shears. Rinse the shears before every cut by placing them in the bucket, then open and close the shears several times. The shears do not need to be dried before cutting. Many rose plants may have fungus growing on them. Some plants will develop bacterial fungus as well. Using this solution will assist with not spreading the fungus or other plant ailments to more plants.

Cutting The Blooms

When cutting the blooms it is best to locate the cut a half inch to an inch above the strongest buds. The bud is where the new branches will emerge. Cut at a 45-degree angle away from the bud.
Cutting away from the bud means cutting with the short angle closest to the new branch which is forming.

Disposing Of Blooms

Once the roses are cut they may be disposed of by placing them in a trash bag for curbside pickup. If it is easier they may also be burned as there are no seeds to worry about spreading from deadhead roses.

Growing plants need food, watering and care. Deadheading is a normal part of this cycle in order to grow beautiful, larger blooms on rose plants. Deadheading knockout roses will keep the plants looking neat. This will enhance the overall look of the plant itself while maintaining its place within a garden setting. Deadheading the blooms will also force the plant to bloom more frequently. The blooms will be larger when the plant is properly deadheaded.


Did you know that Knockout Roses care is so easy, many believe the Knock Out helped save the popularity of roses?

The Knockout Rose is the most popular type of rose in the USA today. It was created by an amateur rosarian (rose enthusiast) by the name of Will Radler in Milwaukee in 1989.

It’s popularity is primarily due to the fact it is so very hardy, easy to raise and easy to care for.

Knock Out Roses are actually so easy to grow that they are used in parking lot planters, road medians and other areas where plants are basically neglected.

These cheerful, abundantly blooming roses thrive in these difficult conditions.

On the downside, Knock Out Roses do not make good cut flowers because they have thin stems and don’t last long when kept in water.

In addition, rosarian purists claim that the Knockout Rose bush does not have any scent. Radler is quick to point out that it does indeed have a scent, but it is not the classic rose scent.

He says that it has a light, fruity, sweet scent that is quite pleasant.

Although there are some rosarian purists who find these small faults with the Knockout, it is generally a very popular choice for the home garden.

When compared with other types of roses, Knockout blooms more frequently and more abundantly and is far easier to care for than the typical fussy rose.

How Did Radler Create The Knock Out Rose Bush?

The Knock Out Family of Roses is Radler’s crowning horticultural achievement. He has been a rose enthusiast since the age of nine and is now in his 70s.

He began trying to develop an easy-care rose at a very early age. In fact, he says that fixing roses was one of his first horticultural goals.

Radler approached the problem in a unique way by selecting and propagating roses for hardiness and disease resistance first and flower production second.

He began his project in 1974 and only began meeting with success in the late 1980s when he developed the strain he labeled 89 – 20.1.

This proved to be the breakthrough rose that was easy to grow, disease-resistant and capable of producing billowing clouds of lovely, pinkish red roses throughout the entire summer.

It was not until the early 1990s that Radler’s new strain of rose took off and attained the name “Knockout”.

In 1992 a company known as Star Roses & Plants near Philadelphia signed a contract with Radler to begin testing on his new rose, a process which took eight years.

With the required testing complete, the company filed for a patent and named the new, easy-care rose Knockout. Sales began in the year 2000.

It became quickly apparent that Knockout Rose bushes would be wildly popular. In fact, the stellar performance of the Knockout Rose bush allowed it to be named the All American Rose Selections winner in the year 2000.

Today, with over 90 million plants sold, they have made Radler a wealthy man. These easy-care roses are now available in seven different varieties in nurseries and home improvement centers across the nation.

The 7 Rose Knockouts In A Variety of Colors

1. The original Knockout plant is the Rosa Radrazz. This hearty plant produces single blossoms that range from cherry red to magenta in color.

2. Rosa Radtko is called the Double Knockout rose tree because it produces double blooms. Like the original Knockout, the blossoms are cherry red. This variety tolerates cold a little bit better than its predecessor.

3. Rosa Radyod produces a very pale pink single blossom. It is also called Blushing Knockout Roses.

4. Rosa Radcon is a light pink variety that produces single blossoms. It is also known as the Pink Knockout.

5. Rosa Radtkopink, a.k.a. the Pink Double Knock Out rose is the double blossom version of the pink variety.

6. Rosa Radsunny produces cheery, fragrant yellow roses. It is also known as the Sunny Knockout.

7. Rosa Radcor is a smaller pink and yellow variety that is also called the Rainbow Knockout. It produces single pink flowers with a yellow center.

What Makes Knockout Rose Care So Easy?

One of the main advantages of the Knockout Rose tree is that they don’t require deadheading.

Deadheading is the practice of cutting off spent flowers to make room for new flowers. Knock out roses simply push the old roses out-of-the-way and make room for the new on their own.

One plus in Knock Out roses care – they require little or no use of pesticides because they are naturally disease resistant and insect resistant.

Likewise, they are disease resistant to most rose problems like the dreaded “Black Spot.”

This quality makes them very popular with all gardeners, but especially so with those who wish to keep an organic lawn and garden.

It is worth noting that, although Knockouts remain disease resistant to the majority of Rose diseases such as powdery mildew, they have become susceptible to a malady known as Rose Rosette Disease.

Rose rosette disease is defined as a condition that causes roses to produce strange deformed leaves, flowers and stems. The disease is actually a virus that requires the eriophyid mite to spread and transfer the disease.

The Rose Rosette disease problem was once quite rare, but it has taken a foothold because of the proliferation of blossoms found in a mass planting Knock Out Roses.

How To Care For Knock Out Rose Bushes?

If you already know a great deal about roses, you can toss most of your knowledge out the window!

The question of “How To Care For Knock Out Roses” is simple. These roses offer remarkably easy-care and very low-maintenance.

Unlike other roses, the Knock Out Rose plant bush does well in partial shade to sun.

They can thrive in a wide variety of settings from zones 7 to 11 blooming from springtime to the first frost. They love coffee grounds and banana!

You can enjoy carefree beauty of Knockout Roses by growing them as individual plants, settle them into mixed beds of perennials and annuals, create borders and hedges and plant them in large containers.

Generally speaking, these roses maintain an upright, round, compact shape that grows to about 3-4 feet high by 3-4 feet wide. In extremely ideal conditions, and left totally un-pruned, they can sprawl out to 5-foot tall and 5 feet wide.

Getting Started With Knock Out Rose Care Is Remarkably Easy

How to plant Knock Out roses!

These hearty roses are tolerant of a wide variety of conditions. They are happy in partial shade and in full sun and can tolerate most variations in temperature.

They are sensitive to extreme heat so they are not drought tolerant. If you live in an area that has a very punishing sun you will probably find that your roses do better in partial shade.

It’s good to start out with a well-prepared bed by Rototilling the area where you wish to plant your Knockout Roses to a depth of at least 12 inches.

Be sure to work lots of good organic compost into the well-drained soil to provide nourishment and good drainage.

Remember that roses need lots of nitrogen, and your soil pH level should be about 6.5. Test and amend to ensure these conditions for the best results with Knock Out Roses.

You can plant your roses in either the early spring or in the fall. They are dormant at either time.

New planting should be kept evenly moist during the first month following planting. This will help your new rosebush establish itself well.

5 Smart Steps To Maintain & Care For Knock Out Roses

1. PRUNE: Knockout Roses are generally very fast-growing, and the biggest maintenance job you will have with them is pruning.

They respond very favorably to good pruning technique. It’s best to do your pruning in February.

Begin by removing broken branches and deadwood and then commence shaping your rosebushes. You should open up the inner portion of the bush by taking out interior branches that have become unproductive.

Follow-up by trimming back healthy branches by approximately a third to a half of their original length.

Remember pruning rose bushes is not like shearing hedges. Shape your bushes carefully by following their natural lines.

When you prune your Knock Out Roses aggressively in the early spring, you can expect them to grow back rapidly and bloom with great vigor throughout the spring and summer.

It’s best to perform this dramatic early spring pruning every year and then just provide little trims in between to shape your plants and ensure symmetrical growth.

To see a collection of interesting videos about the best way to prune your Knockout Roses, here.

2. FERTILIZE: You should fertilize your roses monthly from springtime to fall. Knockouts like nutrient-rich soil and ample fertilization.

With a quick search, you’ll be able to find the best rose fertilizer for Knockouts.

Try foliar feeding your Knock Out roses Epsom salt as well. What does Epsom salt do for your roses? The reward – blooms with brighter, more vibrant color.

When selecting an organic matter or Knockout roses feed, use a fertilizer blended specifically for roses.

Early in the spring, you should give them two or three pounds of nitrogen-rich fertilizer for every hundred square feet of soil. Boost this with one or two pounds per hundred square feet monthly through the middle of August.

3. HYDRATE: Water established rosebushes to a depth of approximately an inch once a week rather than watering them lightly and frequently.

4. CONSERVE MOISTURE: Mulch well around your rosebushes to prevent evaporation of moisture.

Always water with a soaker hose or slowly trickling hose rather than a sprinkler. Sprinkling roses can cause moisture to collect on the foliage and leads to disease.

5. PROTECT AGAINST FREEZING: Worried about preparing knockout roses for winter? In the wintertime, your Knockout Rose bush will need little if any care. They are quite hardy from zones 9 to 11.

If you do have harsh winters in your area, you should insulate your bushes during winter by blanketing them in several inches of straw around the base.

After all danger of frost this past, pull the straw away and trim back any areas damaged during the wintertime. Your hearty Knockout will soon be thriving again.

Related Reading:

  • Knockout Rose Winter Care Tips
  • Pruning and Preparing Rose Bushes For Winter

Questions On Knockout Care

Is there a climbing Knock Out rose plant variety?

The climbing Knockout Rose – Rosa ‘Radwin’ PP#19310 was introduced in 2008 from the same originator of the Knock Out® Rose.

  • A floriferous climber reaches 10-12 feet and loves full sun.
  • Winter hardy to USDA hardiness zone 5.
  • A non-fading fire engine red color handles heat well.
  • The foliage becomes a deep burgundy red in the fall.
  • Grow Rosa ‘Radwin’ as a trellis plant or any vertical space you want to fill with color.

How tall do Knock Outs grow?

Most Knock Outs reach 3′ to 4′ feet tall with a width of 3 to 4 feet as well.

I have seen Knockouts planted in the landscape that homeowners have not pruned down in spring reach a height and width of 5′ – 6′ feet overall.

Pruning keeps them inbounds and manageable.

When Do Knockout bushes bloom?

The Knock Outs blooming season is a long one running from Spring up until the last frost.

They rebloom every 5 – 6 weeks and do not need deadheading. However, by deadheading spent flowers the plant will look tidier and cleaner.

Where to buy Knockout Rose bushes?

The entire family of Knock Out Roses is available at most garden centers and online throughout the country.

Knock Out Roses Add Easy Beauty To Your Landscape

With many beautiful and affordable varieties available, it’s easy to see that adding hardy, cheerful Knock-out Roses to your roadside, yard, and garden is a smart choice.

For very little outlay of cash, you can enjoy a bounty of beautiful, lightly fragrant blooms year after year.

This sort of addition to your landscape enriches your personal enjoyment along with the monetary value of your home.

Sources: 1 | 2 | 3 | 4

Prune Your Knockout Rose for a Fuller Shape

A knockout rose grows to about 4 feet high, and it blooms for most of the spring and summer months. Knockouts grow fast and are tolerant of most types of soil. The natural shape of a knockout rose is circular, but they tolerate pruning well, allowing you to achieve a fuller shape while increasing their vitality.

Knockout Rose Soil

Before pruning a plant, make sure it is planted in fertile soil. The soil quality affects how quickly the plant can put on new growth after trimming, or whether the plant can survive the grooming at all. For best results, treat your rose every 2 to 4 months with cotton seed meal, an organic fertilizer that contains most of the nutrients required for plants.

Prune for Health

Ideal plant health requires pruning to remove dead and damaged leaves and limbs. When dead or damaged leaves and limbs are left on the plant, they continue to draw nutrients away from the plant, and serve as a beacon to insects and plant disease. When pruning, use the 1/3 rule, which says you can cut back up to one third of the total growth on the plant without causing it serious damage. This is especially true with knockouts, which are already resistant to shock.

TIP: Our expert gardening advisor Susan Patterson recommends, “Clean pruning tools with hydrogen peroxide before using.”

Prune for Shape

Because of the natural shape of a knockout rose, pruning for shape is a fairly simple job. Just follow the curve of the bush, trimming errant branches. You can remove buds that are past their bloom, but it is not necessary with this plant as the old blooms will fall off on their own. TIP: Susan suggests, “To prevent borer damage you can seal the cuts made during pruning with some white glue.”

How to Prune

When pruning for shape or health, cut branches at a 45-degree angle. Cut to remove straggly or damaged leaves and stems. When cutting back healthy limbs or branches, save the pieces you remove, they can be rooted in potting soil, and produce new roses. Always make your cuts above the leaf branches, to reduce the risk of plant disease and infection. If there are broken branches, trim them behind the break, at the nearest leaf or branch branch.

TIP: Susan adds, “Always use sharp pruners for any rose trimming.”

When to Prune

In warm regions, pruning for health and shape is best done before new growth begins in the spring. Light pruning is ok any time during the growing season. For those in the subtropical zones of USDA zones 9 through 11, roses may be pruned at any time.

Care and Feeding

Knockout roses are not demanding. As long as the soil contains sufficient nutrients and is soft enough for the roots to grow, these bushes tend to do very well. Fertilize the soil with compost, and make sure that your plants are getting at least 8 hours of sunlight per day. Fertilize about a week before spring pruning, to make sure that the plants have the available resources to handle the shock of the trim.

photo (c) Eagerwatchdog, 2010

Should You Deadhead Knockout Roses?

This post and photos may contain Amazon or other affiliate links. If you purchase something through any link, I may receive a small commission at no extra charge to you. Any supplies used may be given to me free of charge, however, all projects and opinions are my own.


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Should you deadhead Knockout Roses? If you do, you’ll enjoy nearly constant blooming throughout the Summer and possibly into the Fall season.

Please note: I may use Knock Out Roses and Knockout Roses interchangeably in this article. Although the official name is Knock Out (two words), there are many who use the word Knockout (one word) instead. I’m one of them, so don’t hate me!

FTC Disclaimer: Some of the links in this post are affiliate links. I explain more here.

First off, we need to ask the main question everyone is curious about:

Many experts — including the fine folks at the company that produces Knock Out Roses — will tell you no, there’s no need to deadhead these roses because Knock Out Roses will do this all by themselves, on their own.

And that’s true to a certain extent.

Knockout Roses will eventually discard their own dead flowers.


Meanwhile, the overall shrub can look very sad with lots of dead flower stalks poking out all over, and fewer and fewer active blooms on the shrub.

But you want blooms throughout the Summer, am I right? Lovely flowers to enjoy each and every day!

I say, “Yes, you should deadhead Knockout Roses!” And there are many out there who will agree with me, although it does mean some extra work on your part.

Benefits of Deadheading Knockout Roses

There are two main benefits to deadheading Knockout Rose bushes.

  1. The appearance of a deadheaded shrub instantly looks much better.
  2. If you deadhead Knockout Roses as part of your Summer garden chores, you’ll enjoy almost constant blooming throughout the season.

Here’s one of our Knockout Rose bushes before I did my weekly deadheading:

This rose bush looks fine from a distance, in part because I regularly deadhead each week, so there’s never too much work to do, to maintain an ever-blooming shrub.

Upon closer look, follow the arrows to see what parts of the Knockout Roses need to be trimmed away:

Sometimes you will find a deadhead candidate hidden among other blooming roses:

And you can also find individual roses that have come and gone as well:

The Best Tools for Easy Deadheading

Before you begin deadheading Knockout Roses, make sure you have a good pair of nitrile-coated gardening gloves — so you can avoid getting pricked by any thorns — and a good pair of bypass pruners.

You can read about my favorite gardening gloves here: My Garden Gloves are the Best

My favorite pruners are these bypass pruners by Fiskars.

I toss all of my deadheading refuse into a basic bucket that I carry around the garden. It isn’t anything fancy — far from it: it’s a used kitty litter bucket which is the handiest thing around! We have several of them…and sadly this particular brand of litter no longer sells it in their awesome buckets, so we are now hoarding them!

How to Deadhead Knockout Roses

Find one of the spent blooms, like below:

Snip it off with the pruners while holding it in your other gloved hand:

And when you see more than one of these together on your shrub?

Just grab both and snip them off. Easy peasy, no fancy cuts to make or angles to pay attention to.

What remains are a couple of short stems that within a week will fall away on their own.

I spend time trimming spent flowers on Knockout Roses too:

There’s only a few petals left, and by this point those petals are about to fall off anyway.

How fast will my Knockout Roses rebloom?

The simple answer is: very fast and almost all of the time!

Look at this picture below:

The first arrow on the left points to a new rose bud already forming, while the second arrow points to more new growth.

As the stems fall away, the newest growth will rise up beyond those old stems and will bloom in about a week.

How often should I deadhead Knockout Roses?

I try to make the rounds and deadhead our Knockout Roses once a week throughout the Summer months.

If you do a bit each week, you should have a never-ending display of pretty roses!

There really isn’t that much of a difference in my before and after pictures, which shows you how a regular schedule will keep your Knockout Roses looking great all the time.

I’m not out there every Monday with the pruners, but I am out there at least once a week with the sole purpose of deadheading our Knockouts.

Happy gardening!

How to Deadhead Roses the Easy Way

Deadheading varies by rose type, but the absolute easiest way is simply to snip off the spent rose at the end of its short stem, above any foliage.

This instantly makes your rose bush look better. Removing spent blooms stops the plant from putting its energies into developing seeds. This spurs the plant to produce more flowers because it thinks it needs to produce seeds.

Hybrid teas need slightly different advice.

Deadheading Hybrid Tea Roses

The general rule for deadheading hybrid teas is to find the top set of five leaflets, then cut the stem below that, at the second set of five leaflets. However, you won’t hurt the rose if you cut it back higher or lower than that.

In late summer to early fall, you can also just cut off the bloom itself. This promotes more foliage and plant growth, which is important for a rose that is heading into a dormant winter period. However, if you do this earlier in the season, the rose produces more flowers on shorter stems. Hybrid teas are prized as long-stem roses, so this practice could defeat that goal.

Deadheading Floribunda and Spray Roses

Prune anywhere below the entire cluster of spent roses where your rose cane (the main stems) are big enough.

Deadheading Shrub Roses

Many of today’s shrub roses, such as the famous Knock Out, are bred to shed spent blooms, often called self-cleaning, so the good news is that you may never actually need to deadhead them. However, you may want to clean them up based on the way they look. Because shrubs produce flowers only from new growth, deadhead only the flower and its short stem. If you cut off leafy growth, you won’t hurt the plant, you’ll just lengthen the time it takes to regrow and rebloom.

How to Prune Roses

Many roses need little pruning. However, in spring you should examine your rose to remove dried or dead canes as close to the ground as possible.

Spring is also the best time to cut back the tops of rose bushes to a uniform shape.

Avoid pruning in the fall. Because pruning of any type spurs more growth, stop deadheading or cutting blooms for bouquets a few weeks before your first frost. As the weather gets colder, roses begin to go dormant, moving their food reserves into their roots. If you prune, this process stops.

You may, however, prune tall modern roses such as hybrid teas and grandifloras down to about 4 feet tall in the fall. This pruning, called “heading back,” helps keep them from whipping in the winter winds.

Get more tips for pruning.

Learn about deadheading other plants.

Tips and Tricks to Keep Plants Blooming

  • By Deb Wiley

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