Dear Tom: Well, I am no expert but I have been growing tomatoes for over 20 years and I never rotated until last year. Well, it was the worst tomato crop I've ever had, but it was the coolest and wettest summer we've ever had here in Northern California. Conclusion? I don't know. I will try to sort of rotate again this year, but heck I grew tomatoes in almost every bed. I garden in 8 4' x 8' raised beds. I have everything on drip systems. There are plenty of "experts" here who can give you far better facts than I. All I can tell you is good soil, lotsa sun, and deep watering have proven a great formula for me. I have been a pretty carefree gardener not worrying too much if I gave them the proper formula. Kind of like life in general, unless something's wrong why change or if it ain't broke why fix it. Just my humble unprofessional experience. I sure have had some great tomatoes to eat and plenty to share and that makes me happy. It was sunny and beautiful here today. It hit 67 deg F Spring is coming! Another Newbie on the list, Mary-Anne USDA Zone 9B Sunset zone 14/15