Green yards without borders can be boring. Borders create interest through a variety of heights, textures, flowers and colors. Layer the borders with the tallest plants in the back and shorter bushes and flowers towards the front. Use evergreens for some of the borders so there's something green and living in the yard--even during winter.
Sketch the yard noting the location of buildings, fences, patios, trees and hedges. Make the sketch to scale. A good scale is 1/2 inch to 1 foot. It's large enough to add details but not so large that you'll need a huge piece of paper. A 40-foot-long and 20-foot-deep backyard would translate to 20 inches long and 10 inches deep.
Look at the views. Unpleasant views can be screened with borders and hedges. Frame scenic views and call attention to them with beds. For example, start the border 10 feet away from the view with bushes 8 feet tall on either side of the view. Gradually decrease the height of the bushes until they are only 3 feet tall directly under the view. Plant bright flowers in front of 3-foot-tall flowers. The decreasing height leads the eye to the view. The flowers add punctuation to get the eye to stop.
Screen off parts of the garden for privacy. Use beds with tall plants. Or, train vines to grow up lattice work you install in the beds. Create a shady nook for reading, with vines growing up and over a bench. Hide the nook with a bed of tall growing perennials, such as delphiniums, butterfly bush and foxglove.
Create a focal point with an island flower bed. Plant tall flowers, such as larkspur, hollyhocks and cosmos, in the center of the island. Surround these tall flowers with roses of medium height up to 3 feet. Border the roses with annuals, such as petunias, zinnias and snapdragons. Edge the bed with alyssum or lobelia.
Add a garden bed full of herbs close to the kitchen. Border it with marigolds, nasturtiums and other edible flowers.
Mix edible plants in decorative borders. Grow pole beans up supports to add height to a bed of lower-growing bushes. Edge the beds with leafy edible greens, such as spinach, kale and chard. One variety of chard--bright lights--has red, yellow or white stems, which add color to a border.
Sketch your ideas to scale on the drawing of your yard. Take the drawing with you to a plant nursery or use it when you're looking through plant catalogs. Jot down the different kinds of plants that you think will work in your yard.
Dig a shallow trench, 3 inches deep and as wide as the border material around the flower bed.
Place the border material such as bricks, bender boards or plastic edging in the trench.
Fill in the trench with the removed dirt patting it down around the border material.
Place bricks flat and level with the lawn for a mowing-edge border. The wheels of the lawn mower will go right over the edging and cut down on the need to edge the lawn with shears.