Pictures are always really, really helpful to diagnosing things. You really shouldn't spray until you know what you're spraying for. That's kind of like closing your eyes in the medicine aisle and randomly taking something. At best you'll get lucky, more likely it won't hurt but won't help either, and worst case can actually do harm. One safe spray is horticultural oil, but there are plants sensitive to it, so you need to know what you're spraying. It does kill most types of bugs and is nontoxic to us and animals, but you have to make sure the dilution is right for the time of year you're spraying or you can harm even plants that are ok with it. It won't help a bit for diseases.

Another important resource is to take sample to your county cooperative extension service- it's free and they are trained to help you with such things. They'll be able to tell you what plants you have, what the problems are and what to do about it.

Have these shrubs been in the ground for awhile? Have you checked the moisture in the soil, too much, too little?