Is this new growth or Rose Rosette disease?

Asked June 11, 2018, 4:49 PM EDT

I moved into this new house that has 2 knockout rose bushes bordering the front porch. I moved here may 1st, and the bushes were in full bloom. Towards the end of may I noticed a lot of dead blooms and holes on the leaves due to a pest (I'm not sure what kind). I treated the plants with garden safe pesticide. It has been about two weeks since the pesticide was applied, and now there's a lot of red leaves and I'm worried it may be Rose Rosette disease. The foliage doesn't look frazzled or overgrown necessarily, but maybe I caught the disease early. Or, it could just be new growth and new blooms. This is my first time ever owning roses and I've researched a lot about pruning and deadheading. Should I just trim the dead blooms and wait to see if the red leaves begin to bloom?

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1 Response

I have Knockout roses, too. Looks like new growth to me. You can keep the roses blooming more actively is you trim off the old flower stems the the flowers where the old blooms have dropped. You can reduce the risk of spreading the rosette disease by dipping the shears in a bleach and water solution between cuts.

The rosette disease will create a witches broom effect in the new growth and prevent the new roses from opening fully.