How to Grow Knock Out Roses

roses
Knock Out roses are the epitome of low-maintenance.

Forget what you thought you knew about growing roses! Here’s a family of roses that leaves fussy rose gardeners twiddling their thumbs with no work to do. If you like low-maintenance gardening that packs a wallop, the Knock Out® family of roses are a must have for your yard or garden. Here’s what you need to know about growing Knock Out roses.

rose bush
Knock Out roses can tolerate partial shade.

About Knock Out Roses

You’ve probably seen these roses, whether or not you knew it. Since being selected as an AARS (All-America Rose Selections) winner in 2000, the patented Knock Out roses quickly became the largest-selling rose variety in North America. They’re fast becoming a staple of home and municipal landscapes and parks due to their carefree attitude and showy, summer-long blossoms.

I have several Knock Out roses in my garden, and the most frequent comment is, “Wow, these things just don’t stop!” Knock Out roses don’t make the best cut flowers – they’re thin-stemmed and don’t last very long – but they’re lovely and sweetly fragrant in arrangements while they last.

Advantages of Knock Out Roses

  • Shrub Roses: In general shrub roses are the most carefree of all rose types. Most Knock Outs grow about 3-4 feet high by 3-4 feet wide in a naturally compact, upright, round shape; although I’ve seen them sprawling upwards of 5 feet if they’re happy and unpruned.
  • Hardy to Zone 5: In colder climates, Knock Out roses can be protected for the winter or brought indoors in pots.
  • knock out roses
          Original Knock Out rose.

  • Long Blooming: Knock Out roses start blooming in spring and keep it up full tilt until well into fall.
  • Disease Resistant: Knock Out roses are resistant to black spot and other diseases.
  • Shade Tolerant: While roses are usually full-sun plants, Knock Out roses will tolerate some partial shade.
  • Fast Growing: Within a month or two you’ll think these roses have always been there, and they’re quick to respond to pruning.
  • Drought and Heat Tolerant: Once established, Knock Out roses can tolerate all but the most extreme heat and drought.
  • Versatile: Knock Out roses can be used anywhere in the landscape, from roadside plantings to garden borders to containers and specimen plantings.
  • Low Maintenance: Knock Out roses need very little care for season-long enjoyment.

Knock Out Rose Varieties

There are several varieties of Knock Out roses to choose from:

    pink knock out rose
            Pink Knock Out rose.

  • Knock Out: (Rosa ‘Radrazz’) The original variety, with single cherry-red to magenta blossoms.
  • Double Knock Out: (Rosa ‘Radtko’) Also cherry-red, but with double blooms, and is a little more cold tolerant than the original.
  • Pink Knock Out: (Rosa ‘Radcon’) Has single blossoms that is a light pink color.
  • Pink Double Knock Out: (Rosa ‘Radtkopink’) Similar to pink, but with double blossoms.
  • Rainbow Knock Out: (Rosa ‘Radcor’) Has pink single flowers with yellow centers. The plant is a little smaller than other varieties.
  • Blushing Knock Out: (Rosa ‘Radyod’) This single-blossom variety is the palest pink of all.
  • Sunny Knock Out: (Rosa ‘Radsunny’) A bright yellow rose with the most fragrance.

Growing Knock Out Roses

For best results, Knock Out roses need:

  • Light: Knock Out roses do best in full sun or partial shade.
  • Soil: Rich, well-draining soil means less maintenance!
  • Pruning: Knock Out roses really are carefree (they don’t even need deadheading!), but if you want to keep them in top shape, cut them back pretty heavily in early spring – they’ll quickly fill back in with bud-covered branches. In addition to annual pruning, I also do an occasional shape-up as I’m cutting flowers, just to keep the plants symmetrical.
  • Fertilizer: Feed about once a month from spring through late summer with a balanced organic fertilizer.
  • Water: While Knock Out roses are drought tolerant, they’ll do best if watered every week or so.

Further Information

48 COMMENTS

  1. Just planted a knock out rose tree for the first time. Some bug is eating it alive. Also it have white spots all over the leaves. Using a organic spray on it but it is starting to look like a plucked chicken. It has some new growth at the bottom but as of today it is very ugly. What can I do? I watered every evening when I first planted, do I need to stop watering everyday? I live in the Knoxville, TN area.

    • I have experienced the same problem. I don’t think Knock outs are that carefree. I suggest spraying them real good with a fungicide until it clears up. I use Neem oil, fertilize then really well and leave them alone.

      • Thanks for sharing your experience with the Today’s Homeowner community, Dianne!
        TH community members helping other TH community members — we love it. 🙂

  2. It amazes me that ease and carefree is more important than beauty when it comes to flowers. People used to grow roses because they were the most beautiful flowers in the world. To me, knockout roses are just one step above sticking plastic flowers in your yard.

  3. I feel that knockout roses are an answer to a person wanting roses for sentimental reasons but does not have the soil to grow the type great grands did. I have tried to grow old fashioned roses as my father. I have been told that due to my location of my yard to try knockouts. So let’s not be a snob about this lovely answer to growing roses. It is also great for a beginner. I was feeling that Mr. Mintz could have been a little kinder in his comment. Good for him and his roses.

  4. We are having the same problem Phyllis. Last summer, we planted several knockouts in a fairly shady area, and this spring, they are awful. Few flowers, most leaves are dying – some have holes. The plants keep trying to put out new growth but it seems a losing battle. Then, we bought some more healthy looking plants with the idea to plant in sunny locations, but set them in shade while we were out of town for 2 weeks to protect them from a week of 90 degree, dry weather. When we got back, they looked the same as the other plants described above. Any ideas/suggestions?

  5. I planted 3 last year. They are in good soil, bloom profusely, morning to early afternoon sun. Only problem is that they have sprawled everywhere and are huge! I didn’t know until I read on here that I could prune in the spring. Also just planted 2 more double pink ones. Will have to try and shape them come next spring. Other than that, they are lovely, but like any other rose, must be routinely sprayed for pests.

  6. I have six red double knock outs, they are 3 years old, this year one is dying, one stem at a time, same watering for all same sun, 5 are great. The one stem at at time I don’t understand. help

  7. A little late to respond to Larry, but Bayer makes a liquid systemic insecticide/antifungal for roses that rescued our knockouts this summer when they looked like they were about to die – same thing, losing parts of the plants progressively. We have also used the same Bayer product on our ornamental cherry trees that were heavily infested with apparent fungus and they too bounced right back. Only problem is that this is definitely not an organic product. It needs to be handled carefully with concern for environmental contamination. Good luck.

  8. I love knockout roses and I have 7 of them in my yard. I have a problem though, when they bloomed this spring it only lasted very short time. My neighbor’s is still blooming and all those that I see in the area are still blooming with tons of flowers. Why are mine not blooming?Please help.

  9. just plant some knockout roses water every day now for a week and lees is turning yellow am i watering them to much need help.

  10. I have knock off roses that have always been red.. However this spring they bloomed pink, and now the flowers that are coming out are deformed. Can you give me some idea what’s going on and what I should do to fix the problem.

  11. I have 3 knockout roses and they bloom profusely, then it seems insects gets to the bloom and it falls apart within a few hours. Today, the blooms were falling apart and there was sign of pests. What gives? What does one use to keep the pest from ruining the blooms?

    Lorene

  12. Planted 6 knock out roses in a flower bed in my back yard that has white small rocks covering bed. Roses bloomed when I first got them but not blooming now. I gave them some chicken manure is that a good idea?

  13. While my wife and I are struggling to keep our backyard alive and somewhat attractive in August our Knock Out Roses are smiling with beautiful blooms! We have them around the pool area and our deck/pergola flower beds. Combined with the Lady Banks covering a large arbor the comments from friends keep coming! I see many more Knocks Outs in our landscape because the old fashion roses just don’t cut it – for the amount of maintenance needed with not much reward from our old roses especially in Texas summer heat.

  14. We live in Dallas, TX. Our 7 very healthy knockout rose bushes died because of Rosetta virus last year (2014). Is it safe to plant knockouts this year or should we plant something else?

  15. To the guy in Mobile,
    Knockouts would be better off planted in the fall as most things would. You can plant now as well but make sure you give anything planted now adequate water as its already mid/late spring along the gulf coast, when it reaches 90 they need water. Also get some composted manure if planting, the respond insanely well to horse manure.

    Mishut,
    I am not a rose expert but if I were you I would find one knock out on sale for $10 and a smaller one at that and give it a try. If it does well throughout the Texas summer and into fall, I would plant more in the fall. Nearly everything is better to plant in the fall in the deep south because not only does it give the roots a chance to take before the heat, the prices are usually better in the fall and there are few crowds.

    Also want to point out I find that these roses take a liking to a thin layer of mulch, I use cedar and pine straw better than most roses, I think its because they are a little more disease resistant. But after the initial mulch there isn’t a need because they tend to take over and are a true shrub. Hope that helps yall some.

  16. Alan,

    I would rather my neighbors plant knock outs than let old heirloom roses become disease infested and gangly. They are also great for areas where you don’t want to do much maintenance and hide eye sores pretty darn well in the landscape like old sheds, trailers, etc. They definitely have a place in an advanced landscape design.

  17. My Knockout roses are really brown & they look like they are dead, they look awful. should i go ahead & cut them all down? are is there any thing i can do to save them.

  18. We thought we were saving a Knock out rose bush that was thrown out. We repotted it in a large black plastic pot last fall. The bush is healthy and huge but it has never flowered. My husband wants to throw it out now. What’s wrong with it? ( it is growing in full sun) We live in Louisiana.

    • Hi Nancy,
      The comment section under each of our posts is for visitors to leave a comment and communicate with each other, it is not intended as a question and answer forum. If you would like to submit a question for possible answer on our radio show, go to https://todayshomeowner.com/radio/ask-questions/ and full out our online form or call (800) 946-4420.

  19. I planted 2 knockout roses last year. One is done great, the other one is not growing as fast and has stopped blooming. It is under a pine tree. The other is not. I have fertilized them. The one under the pine tree bloomed at the beginning of spring and now is not. Help?.

    • Maybe nitrogen rich but lacking micronutrients. Give it a shot of organic fertilizer. Mine did the same but kept putting out one or two shoots. I pruned back the woody stems and fertilized and it really woke up this spring. So much so that i just bought three more. They get me through the lapse of the other flower’s bloom times.

      • Thanks for sharing your experience with the Today’s Homeowner community, L!
        TH community members helping other TH community members — we love it. 🙂

  20. Landscaper took out all day lilies that ran the length of the back fence and planted double knock out roses (that work wasn’t cheap) the third week in June of this year. It is August 3 and it looks like the newly planted roses are on their last leg. No new buds, flowers are wilted, some leaves are brown. I also have single knockout roses I planted two years ago near the shed. They are blooming like crazy, they spread out and look great. I treat both types of roses the same. What is happening with my double knock outs. When I water, I water at the base of the plant usually several times a week in this hot weather and do it at night. I don’t see bugs on them. Have no idea what is wrong.

  21. This info is for persons having problems with growing knockout roses.

    If the leaves are speckled or turning brown simply cut the plant back to 24 to 30 inches in height. Apply fertilizer. I use Miracle Grow with hose end applicator.

    Do not water plants in late afternoon or early evening. Leaves should be dry before nightfall.

    Roses need 6 to 8 hrs. full sun daily.

    Don’t fuss over them They grow better without too much attention. They like neglect better than attention!

    Follow up with second fertilizer application in about 4 weeks..

    Stand back and enjoy!!!

  22. Info for any one having problems with roses or other blooming plants:

    The vigor of your plants are totally dependent on the bed preparation.

    I use my Mantis tiller to turn the bed about 3 to 4 feet deep.

    Till in about 12 inches deep of sand. Next till in peat. Then till in a good layer of organic fertilizer. I use cow manure that has “laid” at least one year. Sprinkle with “Preen” and turn with shovel. Depth of bed should be 3 to 4 feet deep.

    This takes time and effort but it will ensure beautiful, healthy shrubs and abundantly flowering specimens. Don’t crowd your beds. Allow enough space for future growth and multiplication due to natural seeding.

  23. Anyone had success with Rose rosette disease. I’m here in dallas Texas and I hear this disease is epidemic. I have the miniature knockouts and this disease knocked them out in a couple if weeks. right now I am following Howard Garrett’s protocol with peroxide and his garrett juice. any success stories would be appreciated.

  24. Oh, Mr. Mintz, if every flower in the world were the same, what a boring place a garden would be. Even the lowly dandelion has something of beauty to contribute to the world. Perhaps all it takes is opening one’s eyes to the beauty that is everywhere around one.

    Deciding that only one flower is worthy of one’s attention is a sad way to live. I love my garden full of irises and clematis and daffodils and foxgloves and carnations and johnny jump-ups and, yes, knockout roses. It’s bright and fun and pretty. I have no plastic flowers, but I do have a couple of quirky metal flamingos and even a silly little gnome.

    Gardens are for enjoying. Not for snobbery.

  25. i dont know if you can tell me but ive been trying to fine out the name of a rose its yellow with red inside of it hope you can help me because a lady had one but she dident know it’s thankyou

  26. To all – I have probably 40 plus knockouts and I love them. They are prolific and i have enjoyed them – transplanted them with success and so on. I always use the bayer 3 way. But I have worried about the issue of Rosey Rosette Disease since I read about it in 2013….Each year I examine my bushes and I’ve seen what appears to possibly be it but I have just held my breath. One person asked about it but I have as yet heard anyone else say anything and a local nursery acted like I was crazy. Sadly sadly, this may well be the Elm disease of the knock outs. It has been around from around 1940 but the popularity of the knock outs has likely increased the number of diseased plants as well as increased the spread as they can travel downwind. The signs include several things that can be just simple growth but if you see thick stems developing – very thorny – very red /purply red – and the buds look a bit “witchy”, it may be in your plants. There is no treatment and there is no preventative. It is just a destroyer and it doesn’t happen overnight. I have had a lot of poorly developed flowers this spring but we had a very early early spring and then a snap so it may be the cold got a lot of initial buds but I am thinking there is a chance that is part of this. I don’t want to kill anyone’s joy of these. I knew that I would likely see it in my plants back in 2013/I felt there were some signs in my new bushes. But the only thing is to rip them out and destroy them. Do not recycle. They are not carried via the ground so I think you can replant but I doubt you want to plant knock outs. I continued to plant knock outs because they are hardy and they grow quickly and bloom for months and months and months. Here in SC easily April through December. But you need to know that they are possibly numbered in their days . If I lose mine, I lose a wonderful hedge of sorts plus a delightful array of blooms that delight my neighbors. (and cut down on football games next door and parents who do not explain to kids that you play ball in the park) . But being forewarned will help some. I have a good deal of money invested in mine . I bought the large pots and so will lose 20 plus dollars per plant as well as the expensive Bayer products that they require every six weeks. Losing the plants is sad enough – and thinking what I can replace them with that are pretty and grow quickly and don’t go bare in the winter (here, they keep the leaves through the winter). Hope they find a cure. since it has been around since 1940, I think we’re not looking at one coming anytime soon. And the nurseries will NOT tell you about it. I have as yet found anyone who will admit it but it is on the internet from respectable sources. And if it’s on the internet, it’s always true 🙂

  27. I started a garden in my front yard for knock-out roses. . . twice. And each time the flowers just do not survive. Is it possible that the garden may be in an area that doesn’t drain very well after a rain? The first batch I blamed on a very cold winter and lost all 9 plants. Now I replanted another 9 plants and only 2 didn’t survive this last winter. Now a couple more have died. Am I able to add additional top soil, compost, and mulch to amend that garden bed? Could it be that the plants don’t like moist soil after a rain? Soil is rather dry between rains

  28. I have two cement planters I was wondering if I can plant roses in them they will be in the ground don’t know if it’s good drainage

  29. I’m thinking about planting a Knock Out rose in front of a short trellis (52″ high x 48″ wide). I’ve ruled out “climbers” because they get too tall. Is this a practical choice?

  30. Close to Atlanta, I had two knock outs in a partially sunny place at the rear of a large yard. Without pruning, they grew to huge, flowery balls at least 8′ in diameter. Had to spray for Japanese beetles, but otherwise, no insect or disease problems. After several years, they became leggy, so I cut them back to about 18″. Cut them at the coldest part of the winter. They are not dead now, but did not come back at all. I’m about to replace them. I assumed that I cut them back too early, but maybe they contracted the rose rosette disease being complained about. What new growth there is was red in color.

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