Top Questions About Knockout Rose Bushes

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Questions About Knockout Rose Bushes

Asked by
kholbrook on
March 13, 2011

Q. Can You Divide a Knockout Rose Bush?

The bush is about 5 feet tall and 5 feet wide. It’s planted in a corner of a privacy fence and can’t spread out all the way around. I would like to split it so it can grow better and then plant the splits else where in the yard.

Answered by
Heather on
March 14, 2011
A.

Unless it has sent out suckers, it can't be divided. You can check the base of the plant to see if suckers have been produced, but this is unusual for Knockout roses.

What you can do is start new plants from cuttings. This article will help with this:
https://www.gardeningknowhow.com/ornamental/flowers/roses/roses-from-cuttings.htm

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Asked by
sthancock on
April 30, 2011

Q. My Knockout Roses Were Blooming, but Have Quit

My knockout roses were blooming, but have quit. Do I need to fertilize them?

Answered by
roseman on
May 15, 2011
A.

If the temps are in the high 90's to 100's where you are the rosebushes could be just taking a break to gain strength back. Heat stress will do this. Sometimes they do take a break between bloom cycles to regain strength. If you have not fertilized them at all or it has been a month or more, then yes fertilize them now. Make sure the soils moisture is good before and after feeding them as well.

Stan the Roseman
Consulting Rosarian

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Asked by
Anonymous on
May 12, 2011

Q. Powdery Mildew on Knockout Roses

I have a lot of knockout roses that I have had a couple of years and have had no problems, but this spring on mostly my rainbow knockouts and some of my double bloom reds and pinks, they have on them something that looks like powdery mildew. It hasn’t affected the doubles as much as it has the rainbows, as the rainbows look sick. I have tried spraying and cutting them, but it doesn’t appear to be helping. What should I do?

Answered by
Nikki on
May 13, 2011
Certified Expert
A.

Try neem oil. Very effective and not harmful to people or animals. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm

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Asked by
Anonymous on
May 14, 2011

Q. Knockout Rose Tree/Bush

How do I care for it in the winter? Do I mulch it or cover it?

Asked by
Anonymous on
May 14, 2011

Q. Knock Out Red Roses

All the roses have fell off my rose bush.  Is that normal, and will they return?

Answered by
Nikki on
May 15, 2011
Certified Expert
A.

The Knock Out roses are also known as a "Self-Cleaning" rose bush in that they drop all their petals and send out new blooms without having to prune them to bring on the new blooms. Usually they will have buds coming on strong for another cycle of blooms once the old blooms have fallen off. If it has been real hot where you are or even windy, they might need some watering. Keep an eye on the soil moisture and perhaps give them a foliar feeding with some Miracle Gro to give them a boost. The blooms should return in grand fashion soon.

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Asked by
Anonymous on
May 21, 2011

Q. Knockout Roses

Would Knockout roses do well in the Phoenix, AZ location?

Answered by
roseman on
May 22, 2011
A.

The Knockout roses do well just about anywhere. They are hardy and love lots of sun. Here are a couple links for you about the Knockout rosebushes:

https://www.gardeningknowhow.com/ornamental/flowers/knockout-roses/care-knockout-roses.htm

https://www.gardeningknowhow.com/ornamental/flowers/roses/self-cleaning-roses.htm

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Asked by
blackthumb on
June 6, 2011

Q. Problem With Knockout Roses

Why do my Knockout Roses have holes and greyish white spots on many leaves? Also, now they are starting to sprout some red leaves. . . is that normal?

Answered by
roseman on
June 7, 2011
A.

It is hard to say without actually seeing a picture. The holes could be insect damage and the greyish white spots could be the insects if they move. Otherwise it may be a bit of a fungus infection. Spraying with an insecticide of your choice should take care of the insect damage. Be sure to spray up under the foliage too as some insects like to hide underneath the leaves and thus dodge the insect sprays while they continue to do damage. The red to maroon colored leaves are new growth. They will turn green as they mature. Along with that new growth will come more buds for more blooms! That is a good thing indeed!! Oh yes, for the greyish white spots if it is a fungus of some sort, spray the rosebushes down with a fungicide. My favorite and earth friendly fungicide is called Green Cure. It is available on line and at some garden centers and nurseries.

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