Question
I live in Huntsville, AL. Our knockout rose has millions of tiny bright green critters that first were on the bottom side of leaves and the top of the leaves were shiny, sticky looking.  We've used insecticidal soap, blasts of water (which rids them for a day or so). Then they are back. Now they are covering all the new growth including buds.  Since they are supposed to be aphid-resistant, what is this and what can we do?

Answer
I think it is only the Queen of England that gets more positive publicity than Knock Out roses. These are good roses but they are still just roses and will get the same problems as all other roses. They are very hardy, flower a long time and have a good resistance to black spot. However some nurseries are really going overboard in promoting them and are making false statements.
The most common problem in roses is honeydew, which is produced by aphids. Aphids usually live together on buds, the underside of leaves or in the plants' growing tips. They suck out plant sap and excrete a sweet, sticky substance called honeydew, that collects on leaves and stems. Usually spraying them with water gets rid of them but if you have a large infestation then you may have to resort to an insecticide. It doesn't have to be a strong one, anything with the perennial pyrethrum in it will do the job for you. Make sure you also spray all around the base of the rose too. If conditions are right, they will be more so you will have to keep spraying until they all disappear. Hope this helps.