Personally, I loved doing this when I was in the planning stage and here's why...As you can see, I live in Vermont where winter is almost half the year. To look out my upstairs window and envision lovely full grown fruit trees and bushes when, in reality, the ground was a blank slate of snow, helped get me through the doldrums of winter! A great deal of time was spent just envisioning and dreaming. The plants were fully grown and leafed out in my mind's eye.
For me, it was quite important to do because I was limited on space, and I wanted to get all, or at least most, of my plants at once--I'm not getting any younger and some of the trees would take a number of years before fruition. I'm still waiting on most of them. It was kind of like doing a jigsaw puzzle because I needed to know that they would all fit.
I did a general sketch of the shape of the garden. At this point, the front yard was still all (snow-covered) grass, which in spring I'd rent a sod cutter and have lifted out, but I needed to see how deep (south to north) the garden needed to be to accommodate all of the fruit trees, figuring their mature size. If you have acres and acres to play with, maybe a plan would not be needed, but I have one acre total and it's within a village setting right on a scenic highway. It was going to go the length of my front yard along the sidewalk on its south and the driveway on its east.
There was an existing "side garden" on the west between my neighbors and me that includes a Leonard Messel magnolia, some viburnums, dogwood and rhododendrons and the like. It runs south to north perpendicular to the sidewalk and is sort of a woodland garden because the neighbors have a giant oak the shades that area. A lot of the time I spent planning was spent just observing and dreaming. I watched shadows and envisioned new shadows and envisioned full sized versions of all the plants I'd be growing. I wanted the two areas to meld into one continuous garden that curved around from the front to the side yard. Accounting for the shadier aspect, I knew that this would be a good place for things like currants and lingonberries. Lots of observation and thinking time was crucial...and enjoyable. I found that this raised a lot of good questions that I needed to research about certain plants.
I knew the shorter stuff would go in the front (south) near the sidewalk while the trees would go on the north side. I didn't get too fussy and plan out where I would plant the strawberries as they were to be my groundcover and the runners jump all over the place anyway. Nor did I worry too much about the perennials as I could plunk them in around and amongst the larger things--many flowering perennials would be between the serviceberries and the sidewalk for the benefit of people passing...and, honestly, people walking dogs and them wanting to pee--not really keen of my food being spritzed with urine!
By mapping it out, I knew I could use 50 Regent serviceberries and an equal number of asparagus crowns. Just reading about spacing helped me with the ordering numbers. The frontage is 120' or so. Looking out the window at the barren landscape is much easier than when it's summer and I'm distracted by growing things! Visualizing the plants as one long expanse made me realize that I needed to break the length in halves. In my mind vision, I placed an arbor in the middle. Upon it, I could plant any number of choices. I went with pink roses. Once sketched out, I could really consider all of the plant interactions--how one would affect another. Considerations were things like shade or ease in harvest or overall spread and height. I even considered the variations of bloom or fall color!
Because I mapped it out, I realized that there wasn't room for everything. I ended up putting some of the more unruly things out back like elderberries, mulberries and hazelnuts. As far as trees, I knew that I wanted to use the Grow a Little Fruit Tree method. I'll be turning 65 this September, and am not keen on climbing ladders to prune or harvest! This also let me fit much more into my front yard. I have three apple trees, an Autumn Brilliance serviceberry, three pawpaws, two persimmon, a cherry, two figs, a medlar and probably other things I'm forgetting. Some of the trees will be much taller than what I can reach, but they drop their fruit once ripe, so I will have a nice variety of heights.
There are lots of fruiting shrubs as well. For me, being this space is "on display," I planted for visual interest and color as well, trying to spread that out. I do have lots of perennials and bulbs interspersed as wildlife attractors and repellers. (Garlic and daffs) I also took into consideration the window of blooms and harvest, so that there was always something blooming and something ready to harvest. The honeyberries, rhubarb, clove currants and asparagus are among the first and I'll end the year with pawpaws, persimmons and medlar. Surprisingly, I've been harvesting strawberries until November. As you can see, there were many goals that I wanted this garden to achieve: color, blooming and fruiting span, size and attractiveness to wildlife or not. The mapping aspect was crucial because I had limited room in which to accomplish all of these desires.
When planting time came, I did make a few minor tweaks, but for the most part, I was really pleased with how straight-forward it was. I referred to the map often and things went in very quickly. I think I would have been lost without it; after all, it took me hours of thought, consideration and revision with just graph paper and circles! It can be very deceptive to plant a stick and really have a good idea of the size it will become. I remember reading in Grow a Little Fruit Tree how the author states that at her nursery, people really have no idea the actual size of what a small or dwarf 20' tree really looks like. She went on to say that even she never really got a good grasp on that! Having it on a map takes out all of the emotion. It just takes the room it takes and not what you want it to be!