deadheading Knockout roses??

lizbeth-gardenerJuly 8, 2010

I know you aren't supposed to need to deadhead Knockout roses, but can you deadhead them to make them bloom sooner?

If so, where do you cut the bloom off?

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hostared(Z5, IL)

Dead heading anything, even the Knockouts, will give them a clean look.

Cut just under the flower but or a little lower. Knockouts can be trimmed anytime and will continue to bloom. Easy, non fussy rose, unlike others.

    Bookmark   July 8, 2010 at 8:35AM
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buyorsell888(Zone 8 Portland OR)

I deadhead mine on the side that faces my house because they look messy if I don't.

    Bookmark   July 8, 2010 at 11:05AM
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I saw the breeder of the Knockout Roses on P. Allen Smith. He actually said they bloom better if you don't deadhead them. I couldn't believe he said that but he did. He said the Knockout Roses are "self-cleaning". I have to disagree with him because my "Sunny Knockout" is setting hips right now from not dead-heading it good enough. It's also not blooming well. Maybe I should plant the seeds?

However, I have a friend who breeds roses and he said the more blooms you cut to enjoy in a vase, the more your roses will bloom.

    Bookmark   July 8, 2010 at 12:17PM
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sue36(Z5 Maine)

They don't need to be deadheaded? That is news to me! Mine look like a ratty mess. There are the flowers that have gone by, plus the new ones are full of Japanese beetles. I am going to cut ALL the blooms off this weekend and then let the buds open hopefully after the Japanese Beetles are gone. This happens every year and makes me wonder why I bother with roses.

    Bookmark   July 8, 2010 at 1:43PM
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I put out Japanese Beetle traps this year and it did help. I put one in each corner of the yard. I bet I killed thousands of those monsters. I feel your pain! They have ruined so many blooms this year. I hope to wipe their grubs out with milky spores.

    Bookmark   July 8, 2010 at 3:09PM
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hostared(Z5, IL)

you do know by putting out the traps you called most of the beetles in your neiborhood to snack and mate in your yard.

    Bookmark   July 8, 2010 at 3:38PM
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No. I killed most of them in the traps. I rarely see them on the plants anymore since most are dead in the traps now. I have heard others say that, but basically, it drew them to the traps instead of my plants. Those traps really work. I also asked my neighbor to put some in her yard to help out and she did. We won the battle with a little teamwork. I challenge anyone to come to my yard and find one now. I also put out Milky Spores to kill the grubs they come from.

    Bookmark   July 8, 2010 at 3:49PM
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whaas_5a(5A SE WI)

My neighbor doesn't touch her knockouts and they rebloom just fine.

I deadhead mine because I like well maintained plants, not to get additional bloom.

There is no proof that it will or will not encourage more bloom.

    Bookmark   July 8, 2010 at 9:37PM
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Thanks everyone. I love being able to get on here and get answers from people with gardening experience--and so quickly!

I was pretty sure I could safely deadhead, but was afraid I had to do it above a branch with five leaves or something.

Thanks again!

    Bookmark   July 8, 2010 at 11:32PM
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My knockout roses have been beautiful every year. This
Spring they burst into bloom and I dead-headed as usual.
But when the first "crop" of roses were gone, there were no more and I counted 3 buds. Foliage looks great.
What can I do ?????

    Bookmark   July 8, 2011 at 11:44AM
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I use Rose-Tone (organic fertilizer). My Double Knock Out roses bloom virtually non-stop till frosts, although the first flush is the most prolific. Roses are heavy feeders.

    Bookmark   July 8, 2011 at 2:01PM
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mxk3(Zone 6 SE MI)

I want your patio Alina!!

    Bookmark   July 8, 2011 at 4:40PM
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donnabaskets(Zone 8a, Central MS)

Re: Sunny knockout. I have Carefree Sunshine, which came out a few years before Knockouts, is a product of the same company, but didn't get the never-miss Knockout name. It is vastly superior to SK. The blooms don't fade to white in the heat, it doesn't set hips, is self cleaning, and blooms all year. Try it. You'll love it.

    Bookmark   July 8, 2011 at 9:08PM
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Lizbeth, the rule about above five-leaf stem does not apply to knockouts.

For knockouts, if it is a long arching branch, I will usually cut it back a good amount and I expect it will take longer to re-bloom. But mostly I just cut off as little as possible just to keep it neat looking. When there are still some buds close to the deadheads, I just skip that branch until all is dead. I don't want to risk a mis-cut and lose some buds.

    Bookmark   July 8, 2011 at 11:29PM
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I deadhead my knockout roses, my mom does not due to her age. Mine rebloom sooner. I say deadhead.

    Bookmark   July 11, 2011 at 8:07AM
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I have always gardened by benign neglect and had great results. Never deadheaded my knockouts before last year and they were stunning. They did get to big and I did need to prune them back after checking out how and when to do so. But last year a "friendly" helper went and deadheaded all my knockouts while i was having surgery. After that they never really bloomed much the rest of the season. Now I have some knockouts on standards and they are looking terrible. They are not self cleaning like they should and I'm so sad. A Gardener told me they are not behaving because of the beatles ! Ahah ! I have always dusted with 7-dust early season and then gone happily about my neglect. This year I forgot to 7-dust ! The beatles are making a mess of them..... so possibly fellow gardeners, the beatles are stressing the roses into not self cleaning ??? In this case, I will have to get off my duff, slay the beatles, deadhead and get them back in shape for next year's "dust and neglect" program.

    Bookmark   July 11, 2011 at 11:09AM
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mehearty(So ME z5a)

My yard gets deluged with beetles every year. We get them so bad, they have actually KILLED young trees. That's bad. I have resorted to chemicals before, but I would absolutely never use 7 dust. That's irresponsible as heck and dangerous to the birds and the bees. By your own admission, you've been lazy. Get up and do the work you're suppose to do.

    Bookmark   July 12, 2011 at 8:52AM
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linnea56(z5 IL)

I planted a few last fall. They are Sunny something. I was happy with the flush of bloom in the spring. But mine have not bloomed again since. I did deadhead, they looked too sloppy. I have a floribunda with them, that is finally producing a few buds again. But not the Knockouts. No beetle damage, they have not found the front yard yet, though they are working on the back. I didn't know about the fertilizer. I use bagged compost on everything, thought that would be enough.

    Bookmark   July 18, 2011 at 1:07PM
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I deadhead to rid the sloppy mess but they were slow to bloom again.
Could be the awful heat in SC. I plan to try the Rose-Tone to see if that helps. I did put cow manure in the spring on the plants, etc. and they were beautiful.

    Bookmark   July 26, 2011 at 5:48PM
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I remove them if they don't fall off & become a gray moldy blob after the rain.

    Bookmark   July 26, 2011 at 5:55PM
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Bought 2 sunny plants. each was flowering. Planted each and had new flowers. wonderful. All of a sudden, all flowers are gone and no more buds at all on either of these plants. what has gone wrong? what can I do? could they be getting too much water or not enough? should I cut them down dramatically? bought each in a different nursery. Help!

    Bookmark   June 15, 2013 at 9:44PM
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Karolina11(6b Central PA)

Gerrie, are you saying the flowers and buds just disappeared? To me it sounds like something ate them. Can you post a photo?

As for knockouts, mine look better deadheaded too and rebloom much more quickly. I just cut below the flowers. I only follow the five leaf rule in specific hybrid teas, not shrub roses, and then even then it isn't all the time.

    Bookmark   June 16, 2013 at 2:52PM
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