Question
We have several knock out roses which we are growing in large pots on our patio.  They get at least 8 hours of full sun each day.  We purchased and planted them in pots approximately three years ago.  They have been healthy until this year.  There are entire branches of the roses on which the leaves are yellowed and have died while other parts are looking fairly good but in obvious need of fertilizer.  I have not yet fertilized them this spring because of the problems they are having nor have I pruned them. One of the roses is a standard so I have been hesitant to severely prune it not knowing if the branches can recover from this problem.  Could you please advise me how to best take care of these roses.  We live in central Alabama.

Answer
You were very wise not to give the roses any food as roses can't take up nutrients when they are under stress. Sometimes rose roots get too hot and die when they are in a container. If the sun is hot and on the pot, the soil heats up and destroys the frail little feeder roots. I would now prune the bush one back hard to try and activate it into new healthy growth. Also the standard just prune it back to shape the head like a ball as that will make it balanced and not put too much strain on the stem. I have found that when a rose is under stress, a mild liquid fertilizer such as fish fertilizer, seems to really perk them up. Chemical ones seem to irritate them when they are not doing well. I would use the fish on the laves as a foliar spray. Try using the fish monthly and if it is just stress that is causing the problems, I think you will see a big improvement.