Gardening in a courtyard presents special challenges. The area may have lots of hardscape such as brick or cement patios rather than open soil for planting. Walls provide privacy but are boring to look at. The walls enclosing the courtyard may make the area seem smaller than it really is. Courtyard gardens require planning and patience.
Decide the purpose of the courtyard. Do you need a play area for children? Or perhaps a nook where you can relax after work with a glass of wine? Will the courtyard greet guests as they arrive at your house? What you use the courtyard for will determine how it's designed.
Determine what the focal point of the courtyard will be and design the rest of the area around the focal point while keeping the purpose of the courtyard in mind. The focal point could be a waterfeature, large decorative pot, topiary, or a piece of sculpture.
Review the sunny and shady areas over the course of a day. Some areas may not get the sun you thought it did or be in shade for most of the day.
Select plants that will fit in the courtyard when they are fully grown and will grow well in the light conditions of your courtyard. If you have a small courtyard choose smaller growing trees rather than an oak tree for example that will over power the area. Many bushes that grow 10 to 12 feet tall can be trimmed to look like a tree by removing lower branches from their trunks. Think upwards. More plants will grow in a smaller area if they're trained to grow up trellises and walls. Use pots, containers, and window boxes for plants if there isn't free soil for planting in the ground.
Choose one or two colors for your courtyard, plus white. Any more colors than that and the garden will look jumbled and the area smaller. If the living area opens to the courtyard, co-ordinate the colors of the courtyard (both flowers and furnishings) with the décor of the living area for a finished look.