For the first few years of our garden, I've tried to avoid growing the same crop twice in the same garden bed. But there was a sort of nagging realization that this approach needed to be tightened up. Two crops can be different, but still heavy feeders, and such bed would need a break. Still, this is difficult in a small, mostly shaded, food garden. Sun-thirsty plants such as eggplants and tomatoes only work in a minority of our garden beds.
This year I am following a rotation plan that I'll put the beds on from here on out. This might mean that if I want tomatoes or other heat lovers, I'll go to self-watering containers set in the front of the house, which we cannot use to plant because of the septic field. But I feel pretty good about this keeping our rotation managed, and I'm grateful to have found such a helpful plan. Check it out at the "Harvest to Table" website! Beds are divided into four plot groups, then rotated through on a four-year plan. The authors recommend grouping together in one's garden, but since I'm not beginning with a new space, that didn't work here. Also, I think scattering plot types has other benefits in my garden: the shadier spots are divided among groups, and insects attracted to a particular crop have to work harder to find their food of choice!
Always nice to have a nagging concern addressed!