I started planning the 2007 season during the summer of 2006 when garden successes and failures were fresh in my mind and before I ordered fall-planting bulbs or seeds to start indoors. If you have not begun to plan for next year this is a good time to start, as the growing season winds down. I keep a garden journal and make a master plan that includes assets, liabilities, and dreams. Knowing what you want saves time and money. It is just a guide. Draw a map of the garden. Annual maps keep track of crop rotations in the vegetable garden and which plants grew well in which locations. Have a place in your journal for "great ideas". Experimentation is fun and educational.
Most of the work, and fun, comes long before you plant. The groundwork to a great garden plan is the researching learning, dreaming, and discovering what you want.
Before buying plants think about the larger picture. What walkways do you need? Are there rock outcroppings to contend with or slopes that you must terrace? Consider things like the family's hobbies or preferences. Do the kids need a play area? Plot the layout of your house to scale on graph paper. Note views, permanent features like trees or septic systems, water, hills. Check out the grade, drainage issues, and soil composition. If this is a new garden, please make sure you're not digging into gas lines or telephone cables. Are there natural drainage elements like streams, ponds, wetlands, drainage swales and ditches, moist areas where moisture collects, or a preferable direction of surface runoff? Look at climate, sun or shade at various times of the day, prevailing winds, and extreme variations in temperature.
Keep your ground healthy. Most plants need at least 18" of fertile, well-draining soil. In all, consider soil quality, fertility, texture, pH, structure, moisture, and signs of erosion, and depth to bedrock. Weeds are often indicators of fertility problems. Coltsfoot grow in heavy clay soil, waterlogged or poorly drained soil, acidic or low lime soil. Sturdy redroot pigweed and Lamb's Quarters are found on cultivated soil with a high fertility or humus. Hawkweeds grow in acidic or low lime soil.
Buy plants for specific areas such as shade plants to shady spots and sunny plants into the sun. Do all the necessary soil preparations prior to planting that perfect specimen. Learn beforehand how wide or tall that plant, bush, or tree will be. Not doing so can be a painful lesson. Take advantage of low-maintenance planting options that work with nature, as in xeriscapes, woodland shade gardens or wildflower meadows.
Do you like formal, symmetrical, clean lines? Are you fond of casual cottage gardens? My "jungle" style can hide my neighbor's dog but I love it. The style of your home should influence your garden design. From where do you want to have the best garden view?
There is more to consider. Existing scenery from neighboring yards offer free landscape features to incorporate into your own garden design. Similarly, keep in mind that your plantings might affect your neighbors' view. If you can do it, a well-positioned bench will encourage visitors to stay and enjoy the garden. Structures like trellises and arbors to screen out nasty views or create privacy. Fragrant plants situated close to porches and gateways are lovely. Plants do much for us. Evergreens provide year-round structure, foliage contrast, definition to specific areas, and create focal points. Greenery can define spaces and walkways, offer focal points, express your style, break up open spaces, enhance other features, suit the scale, capture the changing seasons with plant choices that bloom at different times and compliment evergreens in winter. Containers bring fragrant plants to your sitting area, add interesting focal points, and fill gaps left in the garden by perennials that have finished blooming.
Specialty gardens are both challenging and rewarding. Small space gardens have special issues. Instead of freedom to create a special effect, in small space situations, the plan is often required to solve particular problems. Consider scale. A small space may not accommodate huge trees or very large and boldly-leaved plants. There may be specific problems like light-blocking trees or buildings. Are there eyesores that you would like to block? Extra work and time might be required. Personally, I would just downsize, simplify, pick plants appropriate to site conditions, and have a ball making small but delightful "displays".
Finally, share your knowledge as well as what you grow, and do have fun. Mistakes are serendipitous learning opportunities.