Consider the garden in the morning, at midday, and in the late afternoon; it can be a completely different garden. What is bright at breakfast may spend most of the day in shade, while what is narrow and hot against a fence in the morning may soak up a great deal of heat when the sun is lower before it is gone. Sketching in the paths, planting beds, and a seat for sitting is often easier after we spend a moment observing a space to see how the sun really falls. This small investment of time can save a lot of rushed planting that could have come about from a simple mistake about which plants to put where and when.
Pick a corner of a garden and take a look at it three times, morning and early afternoon and in the evening. All you need is a garden notebook, pencil, and maybe a few pictures taken on the site. Mark the areas that are mostly sun, partly shade or mostly shade, are dry or damp, wet or dry and open or sheltered from the wind, by a wall, tree, or fence, etc. If you are looking at a balcony or courtyard, note the influence of a balcony railing or walls and overhead structures that cast shadows. This is all part of your base plan from which you start all decisions.
There is more to sun and shade than just what plants will survive. If you put a seat area in full sun or partial shade, will the people who use it like that? Is a garden path likely to be damp, muddy, or slippery for a long time after rain? If a spot needs frequent watering or is dry all summer, where will you put your plant pots? Does the spot suit any particular kind of bed or planting? If a sunny spot is at the front of the garden, you may choose plants that give a lot of bright color, but will it need lots of care and watering, and lots of mulch? A shaded area at the side may be a quieter place, but the color and texture and the shapes of the leaves become much more important. You may still see some flowering plants, but they are unlikely to be the major feature.
Many planting plans fall down in this way because you pick your plants first and then check if the conditions are right for them in the site. You might go out and buy perennial flowers or a small shrub or ornamental grass because it seems pretty, but then the garden bed is too shady, too dry, and you realize that the adult size of the plant is just too big for the space. Watching first helps to slow down that thought to a better process. We ask not, “what should I put in there?” but instead, “what can I put in that part of the garden?”
If you are drawing a plan, just use simple notes and shading on your sketch. Maybe use a very light line for morning sun, a dark pencil for the long afternoon shade, and a circle around any areas that change fast through the day. If you don’t feel comfortable sketching, then print off a photo of the site to mark up with your pencil. You are not producing a final design drawing. You are making a useful map to see if your planting bed or seating area or feature location is the right choice for the conditions on the site.
Ask yourself some questions. Would anyone really want to sit in the hottest spot at the hottest part of the day? Is a shaded corner going to need a lot of extra care if it is damp for a long time after rain? Will a larger plant or taller shrub block the sun from a smaller one? Does a fence shade one border as it runs around the plot? We are now relating the sun position to circulation and use, maintenance, and growing conditions, as we can’t separate them.
Once you have seen where the shade falls, things start to make more sense. We might decide to plant the sunniest space, but maybe we would rather sit in a shadier one. A narrow side strip doesn’t have to be a mix of plants at all; maybe just an easy groundcover will work. We are not necessarily stuck with that decision forever, but it is based on something more than a hunch. Before you start filling out a garden plan, notice where the sun is, where it is not, and where it never really gets to.