Sunny KO ought to give good repeat bloom. Removing spent blooms and being sure the plants get enough moisture are two ways you can encourage roses to repeat. Rose Tone or Plant Tone fertilizer is good, one cup two or three times a year.

If shrub roses are tall and sparse, pruning will help them fill out. I think you could cut them back by one-third or maybe one-half this time of year.

This post was edited by michaelg on Fri, Jul 12, 13 at 14:45

If you cut the bushes back now, that will delay the re-blooming--if you don't mind waiting around longer for them to bloom again.

Regular watering ought to bring the shrubs around to re-blooming. Knock Outs, in particular, are known for their good rebloom--so don't let them dry out and go into dormancy.

Kate

If I do cut them down, are they unlikely to rebloom at all this year? Considering their past performance, it seems like I would not lose much.

When I drive around the area, I always see so many shrub roses that are loaded with bloom...but I think they must be a different variety, as the flowers are smaller than my Knockouts.

It will bloom 6-7 weeks after pruning.

On repeat blooming roses pruning usually stimulates new growth. New growth means new bud set and repeat bloom. That's why we dead head the spent blooms right away. It stimulates new growth and more buds to repeat quicker. Since these have never been pruned take them down as Michael said by 1/3 to 1/2 now and shape them as you'd like them. They should fill out some and give you another bloom. Once they rebloom remove the spent blooms right away. If they are out of shape again you can prune for shape as you are dead heading them. You do not have to just cut them to the first 5 leaf set. You can go deeper if necessary to keep them in shape or you can simply snap off the dead blooms just below the hip. What ever works best for your needs. Do this every time they bloom and they should give you more blooms and have the more pleasing shape you want.

I have several of the variety Nearly Wild that I've always had trouble to getting to reflower. First flush is really loaded (especially this year -- bigger than ever). I deadhead as the clusters fade. The growth that follows is long straight shoots that have no buds. I cut these back after I determine they are "fruitless."

For food I usually use composted manure in the spring as the shrubs emerge. After awhile I follow the "feed weakly, weekly" process I read about in Fine Gardening. This year I just sprinkled Osmocote around them. Same result of not producing buds, but putting out shoots. I guess I need guidance.

I have a friend who is an excellent gardener and she is a big believer in pruning almost every plant. I have started pruning back alot of things, even cutting blooms off annuals I buy - this takes the stress out of blooming and the plants can make roots - then bloom. It works great.

I have Knockouts, including the yellows which I love. I do prune them back and they just keep blooming. It neatens them up - I also disbud regularly. Dont give up on your roses. They are wonderful with the perennials you describe. Buy a Belinda's Dream if you can find one - totally disease free and blooms constantly. Find some composted manure [I raise horses so have lots], put on alfalfa pellets, cottonseed meal, use Miracle Gro and fish emulsion fertilizer........I have a Graham Thomas rose that has frustrated me with no blooms. A rose nursery told me to fertilize it with Carl Pool BR-61 - sure enough, it started blooming. Dont whack your roses back too much, maybe a third. Keep them watered then watch the new growth come on. It is amazing what roses will do when fertilized. I once read - roses are hogs - feed em. Roses make such a lovely addition to other annuals and perennials - I will bet with some pruning, watering and fertilizing, you will see good results. Be sure and water before you fertilize. Good luck!
Judith

Thanks for the help! I did deadhead them. But have not done much cutting besides that. I'll give it a try, plus the fertilizer.