Question
I live in Houston and have knockout roses planted on the northwest side of the house.  They are really spindly looking but are blooming still.  We had a pretty dry and hot late summer so that may have some kind of effect on them, but neighbors' roses are very lush.  What can I do to grow more leaves on them again?

Answer
Extreme types of weather will often put a rose into stress. Stress shows up by the yellow leaves, frail growth and poor looking flowers. Then when the weather returns to what the rose likes, it will perk up again. However, sometimes if roses are planted next a side of a house, the cement from the base of the foundation leaches out lime and makes the soil too alkaline for roses to grow well. Of course this may not be the problem but it is a common one near home foundations. This spring, prune your Knock Out roses back by a half, then give them any type of fertilizer you have and finally place any sort of mulch around the base of them as roses really do much better with cool roots. Again a house foundation does tend to give off heat in high temperatures. Just make sure they are well watered and don't give any fertilizer when the temperatures are hot as the roots will not be taking up anything when they are under stress and the fertilizer could burn the rose.