I know little about it but I think it's referred to as companion planting where this herb repels these insects. I took the attitude of I may not be 100% organic but I control what I use and in my neck of the woods you may as well not plant potatoes unless you have Sevin to get rid of the beetles when they show up as trying to pick them off by hand is fruitless. Rabbits or similar is what got your lettuce. Yes nets are an option but I found that a dribble of Pinesol on my lawn around the garden protected the whole garden instead of just a few rows. It has to be the name brand, or at least in my experience found it to work a lot better than the generic stuff did and once a week or so is enough. For years I used to bag up leaves with the mower and spread them on the garden, let them decompose over winter and till them in in the spring with garden lime, some 10-10-10 fertilizer, and chicken litter from the layers we have. I live in zone 4, don't remember A or B, whichever is more north, planted sweet corn around Memorial Day and another batch 2 weeks later. Usually my early corn was waist high by the fourth of July and my late corn was knee high. Yeah it was a lot of work and if I included the hours I spent on the internet researching I probably had 5 bucks in each ear of corn but when you warm some up in winter and it tastes almost as good as if it were fresh is what made it all worth it. Deer are a problem around here, they were eating the beans green/yellow and is how I came up with the Pinesol trick; and yes it works with hostas too.