Floating Row Covers are sometimes suggested as a method of keeping plants bug-free. I can only recommend that as a short term option, they have problems if used for very long for bug control. First, bugs usually appear in the heat, and floating row covers tend to increase the heat quite a bit. Not good in hot climates. Second, they are a pain to work around, because you have to lift them off to get at anything, and re-anchor them (they have to be really anchored well in windy areas) - this makes it impractical to use them for things like cucumbers that you need to check and pick daily. Third, they are supposed to let water through, but they don't do it very well. The row cover tends to get heavy and the water concentrates in hollows to drip through all in one place, or it sheds off the sides. Water can also mash it down on the plants, or weigh it down so that it gets muddy and heavier because of the mud. Fourth, once a few of the bugs get under (and they eventually WILL), the fun is over, and the party inside is ON. They'll have a fine old time in there ravaging your plants.