Trimming Knockout Roses in the Summer

There is a question about knockout roses, ‘they’re on their second bloom, can you cut them back?’

So the answer is yes, you can trim the knockout roses back in between their first and second bloom. Ideally, we do it right at the end of a bloom cycle, but if you do it before then, it’s still going to work. You do want to fertilize them heavily, either with all season or with all season and Jack’s Bloom Booster, after you do the trimming, and that will encourage a reflush of growth, and they will set buds on that new growth.

I was thinking about powdery mildew and stuff like that too, with the hot temperatures coming, I think that probably should be something that we should kind of keep an eye out.

I’ve got a couple knockouts at my house, and I’ve had to spray quite a bit this year. We’ve had such a lot of rain, the funguses really grow easy. There’s one called rust, it kind of causes orange speckling or yellow speckling on the leaves. There’s another one called black spot that’s really common on the roses, the powdery mildew, and there’s also a teeny tiny worm that gets on the bottom side of the leaf that likes to skeletonize the leaf and eat all the tissue out of the center of the leaf. 

I use BioAdvanced 3-in-1 on my roses at home, and it really helps keep the insect and the disease issue under control. I know to be friendly to the bees, we want to also spray late in the evening when the bees are kind of back at their home, and it’s the most friendly way to apply it to the plants without hurting our pollinators.

It’s a good idea to do it when it’s not blooming, when the plants are not blooming, but since roses are blooming usually continuously, that’s going to be your best time.

Well, and after a trim back, so when you cut the roses back, as you see that new growth emerging, you want to go ahead and make an application of that fungicide and insecticide. It’ll help protect that new growth, prevent that new growth from getting that disease that maybe an older part of the plant has gotten.

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