I have always loved roses, and when I shifted to a house with a garden, I was thrilled! I cleared a big patch and planted rose bushes. I waited for a couple of months, but nothing much happened! The few roses that grew were of poor quality. However, I did not give up and kept trying with different varieties and used the best fertilizers, and yet the results were the same. Finally, I gave up after working for more than a year. It was while visiting a friend that I noticed the profusion of colorful roses in his garden!! When I asked, he told me that these were Knock-out Roses!! They knocked me out and I am sure you want to know too when to cut back knock out roses.