I keep one. I have a "map" of the garden; my garden is 5 square foot boxes so I numbered my boxes 1 - 5. Then on the next page I made a grid showing just Box 1, what I planted, the date, and if it was planted from a seed, seedling, or established plant. Then I mark in notes, every few weeks or when I note a change such as flowers appearing or produce appearing. I also write in stuff like if I hand pollinated or pruned back, general thoughts about growth, and stuff like that. So on and so forth for the rest of the 5 boxes. This my 2nd year gardening so I hope my notes from last year are helpful.