Before your garden reaches the graph paper, the light has already made many of the design decisions for you. Whether a space is bright and fenced, partly shaded beside the house, or damp and shady under a tree, will dictate where you place focal points, seating, planting beds, and paths. Taking time to read the light and shade will help you avoid a scenario where you draw a tidy plan that, once it is translated into the garden and put to daily use, doesn’t work.
Start by taking a deliberate, slow walk through the space at different times of day. The morning sun, the midday sun, and the late afternoon shade can all be different, even in the same garden. With a sketchpad or a set of site notes, make a note of any particular areas you observe to be hot, bright, cool, sheltered, windy, or wet. You don’t need to measure these things to the inch yet. Your task is to look for patterns; for example, what wall casts shade, what part of the patio gets the most sun, what corner is always dark, or how quickly the edge of the lawn dries after rain compared to the rest of the lawn.
A good exercise is to make a rough draft of a base map with the main fixed features including the doors, windows, and walls of the house, the fence lines, existing trees, paths, and any other hard landscape. Now using the lightest of pencil marks or colouring pencils, identify the brightest areas and the shady ones. Make these marks loose, as you aren’t going to turn this into a plant design right away, but simply use it as a visual record of the site. Once this is done you may wish to start thinking of places where comfortable seating might work, where to keep the main path away from muddy areas, or even which planting borders need shade-tolerant plants.
A common mistake when beginning to read the light in a garden is to assume a uniform amount and quality of sunlight across the garden area. You can have full sun to the front of the yard, partial shade to one side, or full shade underneath the shrub layer or tree canopy. Often the lack of these light differences gets people designing their plantings based purely on the colour or flower size, not the light requirements. Sun-loving perennials and shaded ground covers should never be designed using the same approach. Knowing the light helps you think in a more realistic way about the outdoor room and to divide the garden into more realistic outdoor living areas.
The light also changes the way you will see the space. You may have a focal point or garden room placed in a shady corner and it won’t be seen from a major viewpoint, whereas a brightly coloured planting next to the pathway might become overbearing, especially if the rest of the space is rather quiet. Think about how you will view the space; go to the windows, doors, and seating areas and also to the entrance, and look out across the garden. What does the eye see first? Consider the way light might bring to life texture, edging, mulch, plant height, and seasonal colour changes; think about this not just as a horticultural consideration but as part of the landscape design itself.
Shade isn’t inherently a bad thing; it can offer an opportunity to create a quiet seating area, a softer colour scheme, and perhaps a focus on leaf texture rather than flower power. The trick is to know what type of shade you’re dealing with. Light shade under a small tree can be different from partial afternoon shade, and deep shade underneath a dense planting is still different again. Make sure you distinguish these various types of shade in your sketches or notes. When you’re ready to test some of your ideas for plant groupings, you can be careful not to put together plants that love the sun with plants that prefer shade.
Once you’ve recorded your first draft of the light and shade in your garden you can move back to your sketch and make any necessary adjustments; you can move planting areas to better locations if it becomes clear that the conditions just won’t work. A narrow path may need to move or widen if it is in a damp shady corner, and remember to maintain access around your beds for future pruning, watering, or mulching. One sign of a successful plan is that it starts to answer the question of “why?” for where you have placed everything. A good plan begins to make the garden sketch less of an exercise in how to fill an empty space, but a more useful and interesting response to the particular site itself.