In many places, land is costly or scarce. Many homes and apartments include only a tiny porch, balcony, or patio. Others have a very small yard backing up to the neighbor's fence or the back side of another structure or a smaller part of a larger garden, such as a side alley. But even a single, well-placed container can add personality and color to a small space. Make the most of it.
Size up your space.
Measure it physically. How much space do you really have?
What is the climate and exposure in your space? Does it get a great deal of sun or shade?
Look at the surroundings. Is there something you wish to cover up or conceal, such as a wall, fence, or utility box? Is there something you wish to preserve or incorporate, such as a nearby tree, a view, or other surrounding landscape?
Check out the soil. If your small space has soil, is it clay or sand? Does it support other plants, even weeds?
Figure out where water will come from. Do you have someplace to hook up a hose to water the plants? If so, consider a self-coiling hose with a nozzle that will turn off the water. Get a hose sized for your space. Otherwise, get a large watering can.
Choose a purpose for your garden.
Is it purely decorative, or would you like to grow a few herbs or food plants?
Decide where you will be when you look at this garden. Will you be out in it or will you mostly view it from indoors? One or two chairs and a small table can make a small garden an attractive retreat in which to sit and read.
Clear the clutter. If you are serious about making a garden here, try to find someplace else to store the mop. Many communities discourage the use of outdoor spaces as storage, anyway.
If you must store items in this area, such as if this is the only place for your bicycle, at least minimize the size and number of items stored. Discard or remove any items that are not necessary and give yourself space to organize and access the rest.
Use perspective. Place larger, brighter specimens closer to where you will be viewing them. Use more muted colors and smaller features (leaves and flowers) further away. This helps to give the illusion of a larger space.
Disguise the boundaries, or at least soften them. If a fence or railing is the prominent feature in your garden area, it is very clear how small the space is. Instead, use plants as your boundary.
Use any plants peeking over the fence. If you can see a bit of a neighbor's shrub or tree over your fence, plant some lower plants in a grouping in front of it. Done right, it can look like all three plants are in your yard.
Use garden rooms. You can't always divide the space if it is very small, but if you have a bit of space to work with (say, a small back yard rather than an apartment balcony) don't have all of it showing at once. Have a pathway to another space or area. A small space could be just right for a hidden treasure or for a place to hide out.
Vary the path or patio material from one room to the next.
Make a space for people, especially the gardener. If a path is all you have room for, leave space for that. If you can, though, add a bench or chair.
Go up. Generally, the horizontal space is what's limited. Build a vertical garden, try a taller container planting, or train a climber up a wall or fence. You could also use window boxes or other wall- or fence-mounted containers, or a table or open shelving for more containers.