Answer: There is no guarantee that your roses will be in full bloom the second week of May; blooming is weather related. But, you can get your roses ready for bloom by pruning in January or February. The general rule of thumb is to remove the oldest canes and then select the most vigorous 3-5 canes to save. Remove everything else. Then reduce the height of these remaining canes, cutting to an outside facing bud, in the direction you want the new stems to grow. With the right weather, your shrubs should be in full bloom by June.
As for pruning other trees and shrubs, I agree - a natural look is much more attractive than the roundy-moundy look that most landscapers use. An excellent Pruning guide is a book called Pruning by Christopher Brickell. It should be readily available in book stores or in the library.
Best wishes with your landscape!
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