There's a lot that goes into my garden planning each year! As I've just finished the one for our initial planting in April I thought I'd share it, as it may inspire you to get to work on your own garden plan for this year! Click the plan for an enlarged view.
I let the chickens into the garden for the past couple of weeks to eat and till whatever weeds were growing. They've made the soil nice and loose and ready for planting! They were so happy for some worms and fresh stuff to eat.
We're in zone 7. If the weather has been warm and the extended weather forecast looks good then I'll begin planting warm weather veggies by mid-April. Potatoes, peas and lettuce have already been planted. I've got a ton of flowers and veggies started up in the greenhouse and just ready for that perfect day to begin.
Our raised garden beds consist of last year's boxes: two that are 40' x 3' and 6 that are 16' x 3'. Because Mike put up fence wire to enclose it last year to keep the chickens out of it, we no longer needed open aisles at the end so he added 7 new boxes that are 8' x 30". Then he added a long box to the outside measuring 17' x 2'. I'm concentrating tomatoes and potatoes in these new boxes. Mike says he's building me some more raised boxes surrounding the new fence he's putting up to create a chicken yard. The fencing allows me to trellis LOTS of what I grow and really increased what I was able to grow last year.
First I start with last year's plan. I try to rotate plants so the same thing doesn't grow in the same box for 4 years. (This is a challenge since I grow so many tomatoes, so sometimes there's only 2-3 years rotation on the tomatoes).
Next I take into consideration the path of the sun, trying to make sure that I don't have corn shading the tomatoes, for example. My raised beds have very wide pathways of about 8' apart so it's not a huge problem.
Next I figure out how much space I have after I limit myself on how many tomato plants I'll have. I make a list of all the other stuff I want to grow and see how much I can fit in. This year I want to grow much more food for the chickens so there's lots more lettuce going in for spring plus I'm adding more sunflowers and trying out amaranth for the first time.
I give first priority to tomatoes! I site them first then fill in with everything else.
Since I want to use every inch of space, I research again each year what grows best with what. This takes into account how the plants grow (one box has potatoes which produce below ground, lettuce which has shallow roots and can whose leaves can be shaded by the potatoes, and peas which will grow up the fence that borders the box). I rely heavily on this guide: https://en.wikipedia.org/wiki/List_of_companion_plants