On the Dissing of Knockout Roses


IMG_8481Yesterday I heard master gardening teacher Gene Sumi give his famous talk about basic pruning.  It's but a 90-minute summary of the full course he teaches on pruning at community colleges, but a great beginning for anyone afraid to pick up their first pruners and give it a go.  I'd heard the talk at least once before but still heard some things I'd never heard before.

Like?  What Gene had to say about Knockouts and other landscape roses – that they're bred from the roses that grow wild in Europe and have been used there for centuries as hedgerows.  Commonly called dog roses, they're super-tough, and easy to grow without any particular care, but because they have small flowers, they've been ignored all these years all of horticulture – breeders, gardeners, and especially the rose societies, which favor the highly bred roses with huge blooms, like grandifloras and hybrid teas – the ones that are so disease-prone they require weekly spraying.

Ignored by breeders until the 1990s, that is, when Wisconsin breeder William Radler, who'd been growing roses since he was a kid, decided to use the wild stock of dog roses to develop repeat-blooming, cold-hardy roses that resist disease – the qualities that his 'Knockout' is so famous for.  The qualities that made it the fastest selling new rose in history – 250,000 the year it was introduced (2000).  According to some, it's now the bestselling plant in the whole U.S. of A.


So here's my question.  Why is it that among today's enlightened gardeners – the ones who abhor chemical maintenance regimes – there's so little love for these super-sustainable plants?  These wild-type plants.  Wild is good, right?  If they were native to the U.S. would these super-common plants be more appreciated?

Hey, maybe that's why they're ridiculed – because they're so common.

Me, I love common plants.  Maybe it's because I'm a low-maintenance type, drawn to plants that succeed with little intervention.  And maybe it's because as a gardening coach, I need my garden to exhibit the easy, common, and inexpensive plants that I recommend to my clients, most of whom are new to gardening.  So I grow not just landscape roses but other common and sometimes disparaged shrubs – like spireas, weigelas, and cherry laurels.  Good thing I've never claimed to be a plantswoman. 

Go ahead.  Tell me why YOU don't like Knockouts and landscape roses as a group.  And it had better be about more than the lack of scent.  Really, how often do you get close enough to smell your plants, anyway?

Top photo: Knockouts on Capitol Hill (see the Capitol building in the distance).  Lower photo: Knockouts at the beach with daylilies.


  1. ‘Cause we all want to be unique? “Cause we are “gardeners” and we want to garden and these are too easy? “cause you see them at gas stations? Me, it is because I got burnt on the landscape roase thing with the meidiland(sp). They lied to me about them. They got twice as tall and four times as wide and took over the world. They were the worse thing to rip out.

  2. I sell plants for a living, and I have found that one of the first plants new gardeners want is a rose. I know if I can steer these novices to a Knockout they will not be disappointed and may come back for other things. So put me in the “like” column.

  3. If they smelled as good as they look, I’d get one right away. As it is, I’ll probably wait a while longer. There are plenty around to look at in other people’s yards and public plantings. And they always look good.

  4. I attended the seminar with Gene yesterday also… and I definately could listen again and again. Lots of info there. My garden has knockout roses, weigelas and cherry laurels too. Hey… I like them.

  5. Because they are usually stuck in traffic islands in parking lots, just the rose bush and ugly mulch in a sea of pavement. What single plant could look beautiful like that?

    Poor things…

  6. Once-blooming Old European roses. Just as easy, ten thousand times as beautiful, plus scent.

    You just have to be satisfied with one rose binge between late May and mid-June.

  7. I grew up with dog roses and I adore them. They is something delicate about their blooms, something soft, they peek at you with those golden stamens and make you want to bury your nose right in the flowers. The hips arguably even more gorgeous, almost red, and they’re tasty. There is such subtle variety of color for dog roses, but it’s the open shape of the flowers that is so inviting:


    Knockouts? Are nothing like that. They look exhausted. They look excessive. There is such a thing as too much, too bright, too loud. I know they’re easy to grow and I don’t mind them where appropriate: parking lots, along highways, softened with grasses or other plantings. I hate them in parks, they seem to fix time into some extended, unnatural June, so much that they tire me out. Give me seasons, give me some evidence that plants aren’t made of plastic.

    But then again, I hate daylilies too, so take all I say with a grain of salt.

  8. I’m with Michele on this: I’d rather binge once a year on fabulously beautiful, scented OGRs than spend a summer looking at those shapeless, scentless landscape roses.

    The dog rose itself is beautiful. It makes me sad to think it’s been bred into those nondescript so-called Knockouts.

  9. Could be their marketing push – where they promote Knockout roses in regions where they don’t grow that well. Course all plant breeders do that – fudge a little on performance.

  10. My beef with Knockouts is that I don’t know if it’s an issue of poor info on the tags or what, but these are another tiger cub plant for homeowners: looks cute and innocent when you first get it, then you turn around and it’s eating antelopes on your front walk. 7’x7′. It’ll fill it.

    Other than that, if I have a homeowner that geeks out on plants and wants something exciting, I steer them to old-fashioned roses. Actually, now I steer them to an heirloom rose grower in Fredericksburg who I think is awesome. If it’s the usual homeowner story of “we commute to a 60 hour a week job in DC then have to shuttle kids to hockey, choir, dance, and ukelele vespers so we need low maintenance” – we may look at Knockouts, is they’re the right plant for what I’m trying to achieve. It’s the difference between doing it for yourself (failure is part of the experience) and doing it for others (most folks want bulletproof).

  11. Sorry, it definitely is about the scent for me. That is the reason I will choose a rose, really. The David Austin roses I had at my old house really struggled, because I don’t baby anything, but when there was one, and only one fantastic bloom, the smell would waft across the lawn, and I would go hunting for what smelled so wonderful. At my new house there is one, yup only one hyacinth that survived the previous owner. I had no idea that I had a hyacinth, but one day I was working out in the front garden and I knew there was one somewhere, I found the tired old thing next to the foundation, but it scented my front walk for a couple weeks. I scattered about a dozen around my property for next spring.

  12. RE: the smell – the yellow Knockout rose Sunny IS scented in my garden. When the blooms are out I can’t walk by but be hit by the sweet rose scent…I resisted them for years because of the lack of ‘nose happiness’, but these are winners! I’ve heard complaints that the yellow color on these fades, but I like the variety of color myself.

  13. I’m with you Katie, I find the scent of the Sunny knockout quite pleasant, especially on warm days when the scent will waft across the yard. The “fading” of the yellow color is quite pretty too, as the petals turn more lemony and blushed with pink. I also have the more typical pink/red knockouts, that were here when we purchased the house – three, 3-gallon pots in an 8’L x 4W’ space (plants maybe 2’H x 2’W at the time) – that 3 years later are 6’H x 8’L x 6’W, LESS one plant that I transplanted to another location because they were growing out of their allocated space.
    I can understand the opinions that these aren’t “desired” plants for home landscapes because they’re over-used in commercial landscapes – most home owners, plant lovers or not, want something “unique,” not what they see along newly constructed D.O.T. roadsides or in parking lot islands. But we must realize the reason these plants are selected for commercial landscapes is that they CAN take their tough, environmentally stressed and often neglected conditions.
    If you don’t like them, and don’t want to experiment with what they can provide your landscape(s), don’t plant them. Thank goodness for plant breeders who bring us a variety of plants to choose and learn from.

  14. Don’t judge the quality of this rose variety by where it is sometimes planted… gas stations, parking lots and the like are places these roses are obviously planted and soon forgotten. I have generous plantings of the Knockout Rosa Carumba on the outside edges of my landscape and they are exactly that… a Knock Out! The delicious red-orange blooms last all through the Summer and into the Fall. These groundcover roses are a great addition to my gardens.

  15. If I were going to grow roses for the sake of growing roses, knockouts wouldn’t be my first choice. But I am trying to sell my house and needed to do something with a bedraggled corner bed that would be low maintenance and have curb appeal (having a front yard at all is not something I enjoy but our HOA won’t let me turn it into an edible garden, soo..) and knockouts were the perfect choice.

  16. I haven’t tried the Knockout roses, but I have to say first that I just don’t see the point of a rose with no fragrance. Then I have to say that I have had several hybrid teas for many years, and I don’t do any spraying at all! As far as insect pests go, aphids are the worst, and a jet of spray from the hose takes care of that. If you want to cut down on Japanese beetles, plant peonies by your roses. You won’t eliminate the beetles completely, but they won’t be nearly the pest that they usually are. As far as black spot goes, if you live in a humid summer climate, you have to expect a certain amount of black spot. However, if you religiously clean up the diseased leaves during the season, and put down fresh mulch around the plant spring and fall, you’ll cut it down to almost nothing. Hybrid teas really aren’t the fussy prima donnas that they’re made out to be – it’s just a matter of elbow grease! I mean, sure, if you’re growing roses for the show bench then I guess you’ll need to spray. But how many of us are growing to show?

  17. Knockout roses tough, needing little extra care. What a crock. Plant them in a thin layer of saprolite subsoil over the real soil, give them fifteen minutes less than full sun and they just sit there. I mulched them, fertilized them, weeded them and nothing. I assume the dead parts come spring are winter kill, but it could be some other issue. All I can say for them is that they are clinging to life.

  18. Amen and amen. I love my Double Knock-Outs. When July-August comes to North Texas–with its God-awful heat and humidity–I always have something worth looking at in the garden because of these shrub roses.

  19. I see the comments here about these Knockout roses defying the natural order of seasons, with color that lasts too long… Probably the same people who resent Californian gardens with the similar effect of bougainvillea’s massive color that can last up to 9 months of the year. Different strokes for different folks; I won’t try to convince a “seasons” fan that “year round color” is another valid approach to gardening design. I personally don’t much like roses, never have, but see the value of these rose types for covering large areas with tough growing plants with a long season of bloom. On the other hand, I seek out plants that seem to “defy” the seasons with extra long period of showy bloom, and wouldn’t want to garden without them. Plants that fit that category include both flowering ones such as the hybrid Kangaroo Paws, Limonium perezii, Calandrinia grandiflora, Distictis buccinatorius and foliage color from the various hybrid New Zealand Flaxes(Phormiums), succulents such as Senecio mandraliscae, Crassula erosula, Euphorbia tirucallii ‘Sticks on Fire’, etc.

    I happen to feel that year round color, or at least color over a very long season, is one of the glories of Mediterranean Climate and Subtropical/Tropical gardening. The extra clarity of light and often cloudless deep blue skies here on the Pacific Coast just seems to naturally complement vibrant saturated colors.

    There must be a lot of fellow believers out there across the country, or how else to explain the popularity of “Tropicana” Cannas, Cotinus coggygria ‘Purple Smoke’, and things like Cortaderia pumila ‘Gold Band’ or Red Fountain Grass?

    I wouldn’t try to force the year round color and “endlessly blooming summer” look on those who don’t like it, but there is a market for it, and it is just one of many approaches to garden design. Knockout roses are just catering to that trend, and can look good if used in combination with other plants to complement them. After all, Agapanthus are a “gas station” plant here in California, but people in climates where they don’t grow as easily would kill for those tall spikes of deep blue in summer. Here in California, most people consider them almost a weed, similar to Calla lilies.

    The few roses I ever actually design with, are all repeat blooming climbers, such as Rosa chinensis mutabilis, R. ‘Altissimo’ or R. ‘Joseph’s Coat’. I also think part of my aversion to roses is that I am allergic to them as a cut flower, and hate getting snagged by them when working in the garden. Go figure, as I don’t mind getting scratched up by bromeliad spines or cactus at all…

  20. What’s not to appreciate about a flowering disease free shrub that provides color, texture and form 6 to 7 months (in Nor Cal ) out of the year ?
    In general I dislike roses. Too much maintenance, ruined clothing and punctured skin for the reward.
    The only good thing I can say about maintaining a rose garden to exhibition quality is that the pay is good.
    At least with the knock outs you can take a pair of electric hedge shears and whack them back if need be and they come back just as hardy and disease free.

  21. I met somebody who was involved in developing these roses, and after talking to him, I realized that they really did a nice thing here–created a rose that has no need of chemicals and requires very little care–and hey, it looks a lot better at the gas station than whatever was there before. They were all over the median strips in Pasadena last time I was there. You’ve never seen such a cheerful sight. I bought one for my garden last year. One word of caution: I hear that the original Knock-Out is the best in terms of disease resistance, etc. Some of the newer colors aren’t quite as good.

  22. I just kind of find KnockOuts boring in a “box box store” kind of way. (Everybody’s doing it!) Just looking at antique roses is more appealing than these neon-colored roses. It’s kind of like the streets of Vegas vs. a beautiful country landscape. There’s no contest. But then serenity is what I prefer in a garden instead of cartoon colors. And I think scentless is a very valid reason to reject these roses (the yellows, notwithstanding). I stop and smell the roses in my garden everyday they are in bloom. I think the KnockOut roses are great for folks that need street-side color and that’s all, but I just don’t see how they bring any real gardening pleasure.

  23. Hybrid teas & floribundas require too much of me (pruning spraying, etc). While I’m an avid gardener, I’m also a time-limited one. I just cannot tell the kids that I can’t help them with their homework, go geocaching with them, or attend their sports because I need to tend the roses. Therefore I need something either somewhat trouble-free, or whose trouble I can fit in between algebra questions and Lego engineering issues. Knockouts do that. And I like the way they look next to my lemon tree and native bunch grasses. Even in the winter they are interesting because they have good form … & because I leave the colorful hips on.

    Besides, they remind me of the roses that grew along the fencerows back home. Sometimes just one look reminds me of long walks on steamy summer evenings, my sisters & I stretching over the roadside weeds to pick bouquets of wild roses for Mom.

  24. If they were native to the U.S. would these super-common plants be more appreciated?

    The answer is no. Our natives have to be grabbed up by Europeans, played with over there and then shipped back new and improved before we make much effort to plant them in our own backyards. Pity. So many wonderful plants that need some smart design to go with them.

  25. I love Knockouts. I have 20 in my yard-garden. They are easy. They are pretty. They provide a nice backdrop for my obsession with rudbeckias and sunflowers (which grow up through them and around them).

    Knockouts provide us with some privacy in the summer.

    They are easy.

    Gardening and garden writing is my job, first, hobby second. I like sitting at my writing desk looking out my window at my pretty garden. The knockouts anchor one side of the garden and take care of “pretty.”

  26. If you want a knockout that is more like the original Dog Rose, go for the best one: Blushing knockout! The flowers start out pink, and fade to almost white, so there are several shades on the same plant. Beautiful! (Ditto on the sunny knockout, and it does smell lovely)


    Also, if you don’t want the things to take over the planet, just hit them every spring with hedge trimmers or a lopper and take them down to about a foot above the ground, and they’ll stay the nice 3’x3′ they’re supposed to be.

    Like Susan H. mentioned in the post, if you can adjust your thinking and view the knockouts as a hedge or background workhorse, rather than a specimen plant, it’s a great investment. Avoiding the red and pink knockouts will keep you from feeling like your gas station and your backyard have so much in common.

    BTW, Gene Sumi is awesome! Anyone that can get to one of his classes, or just pop in to Homestead Gardens with a question will always benefit from his knowledge.

  27. Roses are just plain ugly in winter. A thorny tangle, no matter how they are pruned. Give me a plant with elegant ‘bones’.

  28. When you love gardening it’s hard to decide if surrounding yourself with easy to grow, low maintenance flowers are best; or flowers that are a challenge, yet are worth the work in the end because you took the time to grow and treat them accordingly and are rewarded with a beautiful specimen. “Common” flowers are nice to have, but I think that growing something unique is much more exciting than growing a flower you can see on the side of the road.

  29. I am not a rose snob and dont really care for roses at all but someone convinced me to buy a knockout as it was easy care. This is so not the truth I bought a white out and this thing does bloom all summer but when those flower fade the are ugly ugly ugle and instead of deadheading just a few lovely David Austins you have thousands of mushy biege blobs. Just awful

  30. I have never grown Knockout roses because I don’t have enough sun but gave two to my daughter and they both died within two years. Both were a big disappointment, hardly any blooms and the plants looked stressed.

  31. “If you want to cut down on Japanese beetles, plant peonies by your roses. You won’t eliminate the beetles completely, but they won’t be nearly the pest that they usually are.” What??!! Susan, more info! I have probably 15 -20 peonies and am polluted every year with japanese beetles. Two peonies are planted right in the middle of some roses. The roses are covered with the evil beetle. The only rose that doesn’t get the beetles is Blaze, and it is the farthest from any peonies. What do the peonies do to the beetles?

  32. Tibs, the small wasps that you see flying among your peonies just as they begin blooming are a parasitic wasp. When they complete their life cycle above ground, they then go underground to lay their eggs. When the eggs hatch, those larvae feed on Japanese beetle larvae. Again, they won’t eliminate the beetles, but it does help. One thing I’d like to know: do you use those bag traps for Japanese beetles? If you do – stop doing it! Those are phermone traps, and as far as I can tell, all they do is lure every beetle for miles to your yard. Now, I suppose it’s possible that depending on where you live, the whole life-cycle thing might be altered in some respects, or even irrelevant. The other thing I don’t know is if the cultivar of rose or peony has any influence. Hope that helps some!

  33. I like them for the same reason I like “New Dawn”, they are foolproof. If you want fragrance grow some old heirloom varieties as well. I have about 50 varieties in a quarter acre garden. There’s room for everybody.

  34. While I’m not super crazy about the looks of the Knock Outs I have in my garden, I will not remove them. Why? Because everytime I get near them to pull weeds, I come across a beautiful bird’s nest built beneath the mass of thorny branches. Last year it was Brown Thrashers. If the birds love ’em, then I love ’em.

  35. Maybe that the red ones are most often used…too much color! The peachy colored ones are nice and a yellow – haven’t seen it in use yet – would be good.
    Yes, you’re right to point out that they serve their purpose and we have to acknowledge that.
    The roses I grow are all Antique, or Rugosa, and don’t require any care except shaping for size, and they’re all interesting to look at, singles with yellow centers, or cup shaped fragrant. If only the deer would stop chewing on them.

  36. The Japanese beetles (or something) loved the leaves on my new-this-spring Knockout rose. It didn’t get black spot though. I live in Michigan which is tough for roses with our high summer humidity and the Japanese beetles.

  37. I have a few reasons: 1) Yes, I like my roses fragrant. 2) My mother likes them so therefore I HAVE to hate them. 3.) I can drive over to Heirloom Roses whenever I want and get amazing old roses that are gorgeous. 4.) I live in the City of Roses so we have so many damn roses EVERYWHERE I don’t need one blooming like a raving lunatic in my garden. Seriously, we have a lot of public gardens stuffed with roses. 5.) OK, and my confession is that my true love is actually the miniature rose. Their teeth are smaller and they tend not to attack.

  38. I’m sorry Susan, but I do regularly sniff my flowers. If I can smell them without getting close, even better. That’s why I will never grow Knockout. I do grow ‘Carefree Beauty’, which is just as hardy, tough and disease resistant. It doesn’t have the strong, old rose fragrance, but it does have a scent. So I guess I do like the landscape roses. I won’t grow any rose that needs to be sprayed or coddled.

  39. I love Knockout, but there is one thing that worries me – It will become the Stella D’ora of the plant world and no one will look at any other rose – no matter how good it is. People need to know there are many roses out there that do not require spraying and are good repeat bloomers.

    Drift Roses, Flower Carpet Roses, Oso Easy Roses, Polyantha roses, Home Run Roses, Rugosa roses, and Oso Happy Roses are all great low care roses.

    Knock out is the beginning, not the end.

  40. I am happy there are Knock out roses…they make diy gardeners feel like successful gardeners! That could lead to more experiments and more gardeinging YEAH.

    I would probably not use them in my designs unless asked. Yet I am crazy about roses personally. I have “antique” roses, 17 of them! They are fairly easy to care for except black spot when the heat of summer first hits Houston and some only bloom for a week…but I love them anyway.

    I do use common plants when needed…what ever would i do with out dwarf yaupon holly…or cherry laurel compacta, pride of Houston holly,lantanas, sages, hamelias, flax lily, gardenia radicans, and two new ones added to my list are crimson princess azaleas and baby gem boxwoods. Sometimes people just want neat orderly basic front yards….but I always leave room for whimsy, annuals and unique plantings too!
    Thank you all for your time and thoughts!

  41. If I lived in a more rose friendly zone then yeah, why bother with a Knockout when there are so many more choices. But for those in zone 5 or colder the Knockout is one of the few roses that do well with little or no babying. I know there are those that have been bred to handle our cold weather, ugly freezes and heavy clay soil but it is not a very long list. I think if you use them as a single specimen or a very small grouping mixed with more unusual plants they don’t look overdone. And from a landscapers point of view, they are very easy to prune back the deadwood in the spring without being attacked by huge thorns (as they are rather small) part of their added appeal to me.

  42. I too, work in a nursery and steer rose novices towards this plant all the time. The Sunny Knockouts that we sold last season developed beautiful large hips. Even though they are promoted as self-cleaning roses, the plants that we did some pruning on sold faster and looked better at the end of the season. My biggest gripe about this plant is the price we had to sell them at…too high! If our customers knew this plant was considered a “dog” in Europe they would not be happy.

  43. I like Knockouts. I have several of Radler’s varieties, and I enjoy them all. In Oklahoma, the original pink and red with single blooms outperform the others hands down. I do also enjoy Carefree Sunshine which I’ve grown for several years.

    You know I like them as easy care shrubs in the perennial garden. I write about them all the time. Unfortunately, I think the scent gene is difficult to replicate in a disease resistant rose. Not that there aren’t some disease resistant antique or heirloom roses which also smell good like ‘Cl. Pinkie’ for example.~~Dee

  44. Mine bloom underneath a mature Colorado Blue Spruce. I can’t get anything else to do that, at least not anything with a flower you can see without bending over.

Comments are closed.