In my expreince, marigolds have done little in the way of insect protection in my garden. I have never seen the difference in using them verses not using them. This year could be different. After the mild winter the bug population has increased immensely. Farmer hay ( different than hay guy) informed me that the local alfalfa harvest was decimated by aphids. There will be no first cutting locally.
I tend to use marigolds as, what the boys refer to, as a candy crop. I will post about candy crop later. Basically this means that I do not use them as a insect repellent ( as they tend to attract their own insects) but as an edible cover crop.
I have read and have repeated in the past about marigolds as an insect repllent, however I have yet to actually see it work that way here. I have also read that they do little to help. But it is better to be safe than sorry, right? Using them as borders in your veggie garden is just fine. But don't waste those pretty petals! You can find three marigold petal recipes here. Enjoy!