Technique

Rosebushes have to be misted with spray materials for effective coverage.  All sprayers, from handheld to commercial models, are capable fortunately of emitting fine mist sprays.

The method of application is important.  Proper technique requires first spraying the undersides of leaves, where disease begins, starting at the bottom of the bush and working toward the top.

Since mists of spray are being directed upward, a constant "fall-out" drifts down covers the tops of the leaves.  When you reach the top of the bush with your upward movement, most foliage surfaces will already be covered.  One or two downward shots of spray material will finish the job.

Keep spray materials agitated to prevent settling and separation.  Unless you use a power model with a built-in agitator, you must keep remixing the materials yourself.  Handheld sprayers are easy; just shake them often.  As sprayers get larger, they become more difficult to shake.  If you carry one over your shoulder or as a backpack, you might try a technique used by an 82-year-old friend of mine.  When she sprays her bushes, she wears a pocket-size clip-on radio with ear inserts.  She likes to listen to country and western music, and she two-steps and waltzes through the garden, agitating her spray materials all the while.

Your goal should be to spray everything on a rosebush except the blooms.  Don't aim for blooms unless you're spraying for something that attacks them specifically, such as thrips.  Be forewarned, however, that you can't keep all spray material off them.  If a bloom is close to the stage of openness that suits you, cut it before you spray.  Otherwise, spray will discolor the blossoms.  Some spray materials have a way of spreading unevenly.  If you use one of these noncovering formulas, you must add a "spreader sticker" to the liquid spray to insure even foliage coverage.  Commercial spreader stickers are available, but mild household detergent works perfectly well.

One of the first consulting rosarians I met gathered his proteges one Sunday afternoon to teach us effective spray technique.  This otherwise gentle man had away of furrowing his brows if one even looked as if one might fail to heed his advice.  We saw him spray several bushes as he lectured on the importance of complete foliar coverage.  To drive the point home, he said decisively, "If you skip any part of the bush, you might as well not spray at all."  As he said it, he turned from a bush and looked at all of us, but his eyes fixed on me as though I, if anyone, would be the one to cut corners.  I remember squirming but the advice has stuck.