We turned out back garden into an allotment - and literally planted whatever we wanted in rows!
Have grown all herbs, tomatoes, courgette, beans, peas, sweet peas, runner beans, lettuce, rocket, chicory, pak choi, cherry tomatoes, strawberries, gooseberrys, carrots, turnips, parsnips ... etc
We just went for it the first year to see what suited us and our soil - was great fun but didn't get enough to eat out of it apart from the carrots, herbs, tomatoes, lettuce, rockets and all the berries. The boys loved it too.
We just went by what it said on the seed packet!!
Good luck - well worth it
Vickix