Great Design Plant: Knock Out Roses

Ingelnook Farm Inc One disappointment I have with the knock-outs is they bloom in extensive flushes and then keep their discolored petals for the longest time. I end up having to prune off the old blooms, avoiding the new shoots, and this is no easy task for a shrub which is covered with expired flowers.

borshaeity so nice

cjhogelin I agree with the last post re: pruning the flowers. Also, I would like someone to tell me why my "Knockout" (disease resistant) gets yellow and black spot disease on them. I've tried Bayer Rose additives and various sprays to rid my bushes of this disease to no avail. Help!

Christine Gomberg My knock-outs have been destroyed by rose rosette. The damage is very devastating.

chrisens I live in Andover, KS and our entire neighborhood of approximately 50 homes has lost their entire crop of Knock Out roses due to the rose rosette. The mite travels quickly throughout the area and we've been told the bushes have to be pulled out and new bushes can't be replanted for over five years. If the infected bushes were initially pulled as soon as the mites appeared we're told some of the newer bushes could have been saved. Does anyone know of any other solutions to rid plants of the rose rosette?

patscats2 Love my knockouts. I agree, the dead blooms stay on the plant too long, but I don't find deadheading a big deal, do it by hand and it goes quickly. I do wear my gloves because sometimes a tiny thorn will get ya.

dvanvrst When and how do you prune these roses?

Ingelnook Farm Inc Rather than pruning, its more like removing the completed flower. Leave the leaves closest to the flower because it is from there that the new blooms will emerge.

kennedytarheel deer eat my buds and new, red growth!

mynexthome Chemical Control
Although there is no compound that will control the causal agent of rose rosette directly, effective control of mites with certain miticides can reduce the risk of spread.

The insecticide, Avid, is registered for control of both eriophyid and spider mites on roses

Be aware that miticides registered for control of spider mites do not control the eriophyid mites that transmit rose rosette disease. Some researchers have obtained reasonable control with Sevin; however, mites are very small and it can be difficult to get complete coverage. Also, use of Sevin to control eriophyid mites can lead to outbreaks of spider mites.

One Day Interiors I spray my Knockout roses with a mixture of plain dishwashing liquid and water. Keeps the bugs at bay..lots of water and deadheading..full sun...
they are happy. I have attached a pic of one I have in a planter in the backyard.

kaplanss We put in 3 knockouts in late spring and they all blossomed within a month or so. My site has partial shade. How many hours a day constitutes full sun?
Will the plant continue to blossom in partial shade (just a few hours of full sun)?

J. Peterson Garden Design I'd give it at least a half day of full sun--when it gets some shade, I'd make sure it's dappled rather than full or deep shade. It will bloom better the more sun you can give it!

J. Peterson Garden Design Re: rose rosette disease (RRD): it tends to be more prevalent in very hot and dry summers which much of the US has had this year. For our Dallas-Austin-Houston triangle, it seems to be a bit more of a problem in the N. TX area around Dallas. There is no cure--dig up and dispose of any rose affected by RRD including ALL roots to avoid it spreading through your garden.

jandavidson I too am having lots of trouble with black spot on my knockouts. I have tried fungicide spray and extensive pruning. I was told these are disease resistant but I don't find it true on the 10 bushes located throughout my yard. Any suggestions?

Mary Farinella I am new to the Knock out rose family....planted 4 in my yard this Spring. Do I or not dead head them??????

patscats2 Mary, they say you don't have to, but I do. I go out every couple of weeks and just pinch off any spent blooms, not taking any leaves. I wear gloves with some because they do have some tiny prickly thorns that can get you on some varieties.

Jennifer Power I am lazy and do not deadhead. In mid summer I just trim them all down a bit (choose and overcast and somewhat cool day) and within weeks they are blooming all over again. This also helps to keep them a good size as mine tend to get too large for the bed they are planted in. Not saying this is the proper thing to do, it just works for me.

mynexthome Summer 2012 ferocious heat has taken it's toll on our lawns and gardens. Like Jennifer, I give them a quick prune very early in the morning - which gives the new cuts time to seal before the heat of the day. This helps maintain a nice overall shape. I also use a systemic fungicide on a regular basis beginning early in the season to prevent problems cropping up later on. And also spray with dish washing liquid solution throughout the season. These steps and slow watering with a leaky hose prevent most problems.

msslynne I never dead head any of my knockouts, since they are so prolific even into early winter, at most I may cut back a stem here or there to shape-mid season I give them a spray of hard water so everything falls off-they grow right back again and I leave them go from there, they have nice orange hips by the time winter gets chilly-I am in Washington State zone 8b and I peg them out straight once everything is over in the winter

cjhogelin One of my Knockouts is overpowering my walkway. How much can I cut back without damaging growth for next year?

One Day Interiors for the lady wondering if she could cut back one of her roses overpowering her walkway..
I have pruned both of mine to shape as I felt like..one quite a bit..and it did not effect them in any way..they just toook off with even more blooms. The one shown was cut back quite a bit at the beginning of the season.. this pic is just after the cutting and it really took off from there.

jneedham13 I prefer a "free form" bush so I only prune one a year. Garden experts in SW Ohio recommend pruning to 12" when you see the first Forsythia blooms. This keeps them from getting leggy and also keeps them at the size I prefer. I deadhead by hand about once a week (all 27 bushes!). It makes for a prettier showing of the new blooms and makes the bush look neater. Also, the roses in the photo are planted at the front of the house only getting afternoon sun and flourish!