My knockout roses have beautiful vines but do not bloom. We have ferilized them with Rose Food once a month.
They bloomed very little last year also but did have a few. They get full sun from eveln o'clock in the morning for the rest of the day. What could be the problem.
There are a few things that can cause the rosebushes not to bloom as they should. Knock Out roses are no different than other roses in that respect. Please take a look at the article I wrote on the subject at this link: https://www.gardeningknowhow.com/ornamental/flowers/roses/no-blooms-on-roses.htm