I have been using row cover for about a year now. Recently I yanked out some spinach plants that were bolting and that I had already harvested some leaves from. These spinach plants had been under row cover from the time of direct sowing until recently (a few months I'd say, give or take a week or two). Low and behold, two small green caterpillars were there munching. They looked exactly like the caterpillars left by cabbage moths that I see fluttering around in my garden. How they got there is unknown but they found their way underneath somehow. I always end up with aphids as well under my row cover.

I guess the lesson in my mind is that row cover is good, I recommend using row cover, but row cover is definitely not fool proofÂ.

Row covers are not fool proof. they get small holes in them, portions come loose when you are not around etc. And once the insects get under there they have a perfect environment to do their business without interference from beneficial bugs, birds, etc..

So it is up to the grower to check under the covers regularily-at least every 2 to 3 days if not daily. When checking check for holes in the covers, any spots where it has come lose and of course the plants.

I have been using cover for about 12 years and would not do without them but realize they are far from perfect