Pruning knockout roses

alabamanicole(7b)August 2, 2012

This spring I planted a grouping of knockout roses in front. Ideally, I want to keep them at about 3' tall with a nice soft rounded/ovalish shape, which I see frequently in other landscaping. 4' would be okay, especially when the other shrubs get bigger.

I have heard you aren't supposed to prune them the first year, but they are getting quite tall and spindly this year and have outgrown all the other stuff already.

Are roses like fruit trees, where if I summer prune they'll stay smaller and bushier? Or should I just let them go this year and prune them back harshly this winter?

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Every source I've ever read or heard says to prune them in the Spring. They will grow back double of triple after you prune them, so you could probably prune them back to 1 or 2 feet next Spring.

Me? I'm too lazy to prune much of anything. I speak to my plants one time right after planting them, "You're on your own now." :)

    Bookmark   August 2, 2012 at 4:34PM
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I'm mostly the same way, Sundog, but I had so much landscaping to put in after a while I got plant choice fatigue and the roses came home with me!

    Bookmark   August 2, 2012 at 7:44PM
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LOL, Sundog. Even with the best of intentions, most of my stuff ends up on its on. I do have to prune a few things, but if it gets too unruly, I'll tend to dig it up and replace it with something else.

    Bookmark   August 3, 2012 at 10:32AM
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rhizo_1 (North AL) zone 7

Alabamanicole, your roses can absolutely be cut back at this time. If you can do it with a hand pruner, cutting stems back to outward growing branches, it will result in a better mid -season look.

I planted several Knockouts a few years ago and was pretty upset to see that they outgrew their location in a short time. We were going to move them and plant them elsewhere when 'the virus ', rose rosette, moved in....making the decision to yank them easy. That disease is the Achilles Heel of these high performing roses.

Though it's recommended that they be pruned (at least) once per year in the spring, they respond very well to good trims all summer long.

    Bookmark   August 4, 2012 at 8:29AM
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And here I thought knockouts weren't vulnerable like other roses. I can pretty much guarantee I'll get it, then. The downside of a old neighborhood with tons of gardeners and lots of adjacent woods is that if the disease or pest exists, someone has introduced it.

They are blooming so prettily now I'll wait for a week or some for these blooms to fade before I lop 'em off.

    Bookmark   August 4, 2012 at 11:23AM
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rhizo_1 (North AL) zone 7

Too bad that the Knock Outs have turned to be so fragile. WE were part of the problem, planting them in every little nook and cranny. They still have their place; we just need to stop using so many of them.

Robert and I are trying a handful of the 'Drift Roses ', purported to be lower growing than their cousins, the KOs. We selected the Peach Drift, very pretty.

    Bookmark   August 4, 2012 at 7:44PM
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Looks like some of the Drift Roses are trailing. That could be really interesting as part of a large retaining wall, and quite different from the normal choices of things to train over an edge, without the pain of a climbing rose.

    Bookmark   August 5, 2012 at 9:37AM
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First, knockouts can take pruning anytime really. The best way is just to deadhead when a flush of blooms has finished, cutting a little below where you want the height to be becoz you are stimulating new growth. Sources say it is best not to prune before cold weather is coming becoz cold will freeze the new growth.
About the disease problems, You are right about planting too much of one thing, but I have grown many old garden roses, researching the best and most trouble free ones becoz I do not use pesticides and such. The knockouts are by far the best performers.

    Bookmark   August 5, 2012 at 10:34AM
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rhizo_1 (North AL) zone 7

I'm glad you've been so lucky with your Knock Outs. They don't seem to be bothered by anything but the rose rosette virus, which can decimate a large planting in one season.

    Bookmark   August 5, 2012 at 8:36PM
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On the NE corner of Avenue D and 34th Street in Ensley there is one of the most beautiful KnockOut Roses I have ever seen. 8-10ft. tall and at least 10-12ft. wide. It has hundreds and hundreds of blooms. The bush can be Googled.

For the people who do not like the KO rose, this one might change your mind after seeing it. Stunting. A tree in the making.

How large will a KO reach ? Along US 280, on the corner of 119 and Lazy Boy there is about 150 feet of this rose. It has been kept manicured to about 4-5 ft high as a hedge. If it had been left uncut I believe it would hide the Lazy Boy store and probably block part of 280.

As with Crape Myrtle ( crape murder) could we be a Knock Out murderer. I murder at will.... BUT, with these KO's I will give them more room from now on. Wish that I had planted the lot that I have 10-12 feet apart instead of 4ft.

Live and learn? I do it the hard way. When is big better? With the KO, bigger is beautiful.

    Bookmark   May 12, 2013 at 12:33AM
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Tiffany, purpleinopp GardenWeb, Z8b Opp, AL(8B AL)

This rose was a tiny little $5 thing that I put here about 5 years ago. (There's a ramblin' rose to the left and a butterfly bush behind.) I trim the KO often, deadheading it but taking more than just the finished flowers, so it stays small enough to get around. SOooo many acorns sprout there, I have to be able to reach everywhere. Seems like the more I trim, the better it grows.

Bulzi, my Mom only trims hers once a year and they can get HUGE, 10-ft. in diameter, 8 ft. tall. BUT, when she's finished trimming, the finished product is about the size of the shrub pictured below.

    Bookmark   May 13, 2013 at 9:24AM
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I've been brutal with mine and they are lovely small-ish bush now in full bloom with some room to grow -- but I know I will be whacking them back in a few months.

Something is killing the roses in the neighborhood now so we'll see if they survive.

Big roses are pretty in someone else's yard. After the 50'+ hedge I removed when I moved in I won't be letting the roses take over in front!

    Bookmark   May 13, 2013 at 9:45AM
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Tiffany, purpleinopp GardenWeb, Z8b Opp, AL(8B AL)

Nicole, those look super! I love them just as much when they're "used small" like that.

Not that you're in any danger, but it can go too far... Once a week I drive by a house where they planted them in a 12" strip between a picket fence and sidewalk, of all things! Not only that, they're less than 2 ft. apart. I really almost stopped the car to knock on their door and have a chat about it but didn't trust myself to find just the right words... Anyway, that was spring of '11 and they've been keeping them small and it looks really cute. If whoever's tending that stops tending it (for more than a week I'd say,) this is going to be a problem. I'll take a pic today. You'll gasp!

There are also some around the bank across the street, planted about a foot from the wall. After watching the gardener "meatball" everything for a few years, I was really nervous about what I'd be looking at when he put those in, (like would he constantly be cutting off the buds?) But he's done a great job keeping them looking super. Natural form but very small.

I planted the one I showed above with the notion that there's plenty of room for it untended if/when I move. Whoever takes over could move the perennials around it or let them atrophy from increasing shade. Realistically, they would probably end up mowing around the base of it (or chopping it down) out of frustration with the number of acorns sprouting.

I've had such thoughts myself and may end up moving most of the other plants and shrinking this bed, something I've never done before. The more organic matter I add, the more the acorns find it conducive to sprouting, a vicious circle. Unlike other trees I've gardened under, these acorns sprout about all year, not just all at once. (I used to think THAT was a pain - 5,000 silver maple seedlings overnight. Live'n'learn!)

    Bookmark   May 13, 2013 at 11:43AM
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That's been the hardest part of pruning them back -- trying to keep a natural form. I don't care for square hedges.

These roses certainly help you out, though. By growing so fast any pruning errors are quickly hidden!

    Bookmark   May 13, 2013 at 11:49AM
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Pictures are great. Prune to the size that fits in your picture. I sorta feel the same about pruning anything, even to " bonsai " Crepe Myrtle if it needs to fit in the landscape- just right.

I am in trouble if KO's they can grow to be 8-10 feet in one year. Oh well, the house can use some shade. I'll be able to plant shade plants again.

I have a few roses that I am having trouble with. They will not keep leaves on them , but the flowers are nice. They ARE NOT the KnockOut. I do have a thought now and then of doing away with them. Over a period of time could they damage the KO's? Or another type plant - just talked myself into at least moving them down the road . Fooling myself ! They are headed to a garbage bag for the garbage can.

Nothing sentimental here. is or could become, so why worry !

    Bookmark   May 13, 2013 at 1:20PM
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Tiffany, purpleinopp GardenWeb, Z8b Opp, AL(8B AL)

Here's that house, in Samson. Good luck to whoever's done this!

The ramblin' rose on the fence in my pic above, there's almost always some black spots on some of the leaves but the KO next to it never gets them. I don't make any effort to clean up the fallen spotted leaves. The more banana peels I put at the base, the better it looks (but that's true of any rose that I've had.) AFAIK, rose rosette is the only known disease to which KO's are vulnerable.

Probably the best thing for any roses is to be scattered, not bunched together where any kind of malady would thrive in a large monoculture. Or at least companion-planted with garlic or whatever plants are supposed to be symbiotic with roses. I'm way too impulsive to try that kind of stuff but it intrigues me.

    Bookmark   May 14, 2013 at 5:22PM
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Samson picture looks nice, very nice. Bet alabamaicole can ID every plant there. I enlarged the picture and could not. Scratched my head.

You really got me worried about the roses getting rose rosette. I am planting a LARGE amount of roses and after reading here and other sources I will prune some for sure. I will start to space out the roses from each other. Just can not pass up a sale on anything.

Cascade Rose 1974 (?) is by far my favorite. The start was given to me by a dear woman -Hazel- . She brought it to me in a hanging basket. Little did she know what a grand plant it was. She wanted to know if I wanted to do anything with it and boy did I. Sold and gave away countless ' rooted babies'.

Enjoy taking one plant and multiplying it hundreds of times.

Garlic is great anywhere and everywhere if snakes seem to be a problem. It is a great picturesque plant if given enough sunshine. There is lots of garlic here to dig to place around thru the roses..... In my head it looks just right. Thanks. It is difficult for me to connect the dots and then remember that I did, much less mix and match plants.

    Bookmark   May 14, 2013 at 8:14PM
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madabouteu(8A - central Alabama)

One of my Knockout roses is about 10 feet tall and wide. The other twpo are only about 4 feet tall.

    Bookmark   May 17, 2013 at 9:54PM
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Reckon the care and maintenance guide that is placed on plants can not tell it all. Knockout has 4-5 feet high and wide. Strong tolerant rose, as are the Drift Rose.

The roses in the old Ensley area of Birmingham seem to be trying to out do each other this year. This maybe a great place for the Rose Society to look for roses of the past. (before they are burned or bulldozed.)

Usually the amount of rain that we have received this year during blooming is bad, IT DOES NOT APPEAR TO BE, thus far. I could not do away with the roses with the black spot, I will deal with them awhile longer.

    Bookmark   May 17, 2013 at 11:15PM
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Tiffany, purpleinopp GardenWeb, Z8b Opp, AL(8B AL)

A few days ago, I trimmed this pretty heavily again, so it's actually shrunk, for the moment. I took a lot more off of one side 'cuz I have to get in there and pull sprouting acorns every day. It had just finished a flush of blooms. Put a couple banana peels near the base, then it rained several inches. (Whew!! It had been about a month.) Starting to see red nubs of new growth again.

Bulzi, there's a red once-blooming rose on the fence near this KO and it always has black spots, and is basically really ugly except when it's blooming. Over the years, I've woven it excessively into the CL fence and that's improved its' vigor a bit, the blooms are great and by now the rose is just anonymous green stuff behind a butterfly bush and this KO.

    Bookmark   June 5, 2013 at 12:26PM
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You just can not beat a post - that - includes a picture. That one time bloomer maybe a "Seven Sisters" rose.I have a lite and a dark pink. Ramblers !!! The rose was planted ( I was told) along US 280 over 70 years ago. I ended up with a few on my side. Trooper !!!

Picked up some 'Drift' roses and anoTHER 'Lady Banks Rose (which happens to be the largest rose bush known). The Drift blooms reminds me of the Seven Sisters.

My favorite plant is always one that I do not have , even if I already have a hundred of them. If it can be eaten I favor it a lot. ToMaToEs !

Herbs, I take, mainly come from bottles. Purpleinopp, alabamaicole on the post of' Alabama best weeds' really hit it on the head with Hemlock. I am 99.99% that is that plant. When it first come up it reminds me of a fern. Attractive in most every way, as is the Angel Trumpets, AND can be death to the partaker.

Back to the KO rose. SOOooooo many -new- roses introduced that a Dead Rose Nut from 1950, would be in bliss today...tho, those petals from the past are the best keepers of all.

    Bookmark   June 5, 2013 at 4:27PM
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Tiffany, purpleinopp GardenWeb, Z8b Opp, AL(8B AL)

Yes I agree! I had a collection of roses so old they didn't have names in OH. Pass-alongs and dug-ups... They always looked great, bloomed great.

One in particular I really miss, a rambler that had clusters of 4-10 smallish white blooms with the slightest hint of pink on the outer few petals. They were incredibly fragrant with the clove'ish fragrance I love in a rose, about a hundred petals each, a very long bloomer. I found it at the edge, almost under the deck at my last house up there, moved it to the sun (by chopping most of the roots off to get it up,) wove it in the CL fence. After a few years, it was a real "wow'er" and it was probably just getting warmed up.

The only roses I ever see for sale are KO or hybrid teas.

Since you like pics, here's one of the above-described rose, from 6/8/03.

    Bookmark   June 5, 2013 at 5:06PM
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Tiffany, purpleinopp GardenWeb, Z8b Opp, AL(8B AL)

Sorry for the double post. When it said "500 internal server error" the first time, I assumed it had not posted.

This post was edited by purpleinopp on Wed, Jun 5, 13 at 17:08

    Bookmark   June 5, 2013 at 5:07PM
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Malissa Allman of the University of Georgia extension has two very nice videos on pruning one year old and very large Knock Outs. She is wonderful to follow on YouTube with practical hands on advice for the southeast.

    Bookmark   August 26, 2013 at 11:40AM
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Malissa Allman of the University of Georgia extension has two very nice videos on pruning one year old and very large Knock Outs. She is wonderful to follow on YouTube with practical hands on advice for the southeast.

    Bookmark   August 26, 2013 at 11:47AM
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