Is it just a few sparse holes or are you loosing a significant percent of your foilage? My experience outdoors is that you will get a few holes in your leaves here and there but it wont hurt anything or cause any significant damage. I have used Neem in the past when they are small and then just leave them alone once the get to say about 16 inches or so. I guess it depends on where you are at and what kind of pests are present in what numbers. I had much more problems with bugs (mites and gnats) several yrs ago when I used to grow indoors. Outside everything seems to take care of itself. I guess there is as many predators as there are plant suckers. Anyway, try the Neem. It's fairly cheap, works well and its safe. Hell, they say people in India chew on the stems, make teas out of it and such. I have used it sucessfully on flowers and shrubs around the house. Not quite strong enough for the japanese beatles on roses though, unless you spray it like every other day.