Privacy screens are indispensable elements of garden architecture. They can screen disagreeable views, block visual and physical access and create a sense of privacy. Formal hedges are a strong element in the landscape and require regular maintenance. Informal hedges can create a naturalistic backdrop for other plants. Careful evaluation of the site and thoughtful plant choices are important components of privacy screen design. With a little planning, thoughtful plant choices and proper planting, a privacy screen can make your garden feel cozy and safe.
Investigate how high the privacy screen needs to be to screen out distant objectionable views. Attach survey tape or an old sheet between two broomsticks and enlist a couple of friends to hold the sticks where you want your privacy screen to be while you observe from different parts of your garden. Ask your friends to move the tape, or taut sheet, up or down to find a height that blocks what you don't want to see. Often the necessary height will be surprisingly lower than you initially thought.
Consider the desired function of the screen. If you want the screen to also protect against harsh winds, or pedestrian traffic from an adjacent sidewalk, then it needs to be dense and evergreen. If it screens an object in the distance, a more permeable screen can allow more air circulation while still creating a feeling of privacy.
Decide how much space you want to devote to your privacy screen. Remember, you will need to access both sides of the screen for routine maintenance. Plant evergreens in a double row to make a dense hedge where space is ample. Plant tall, upright shrubs, like privet or bamboo, where space is tight.
Select plants that fulfill your requirements for the screen's desired height, width and function. Evergreen shrubs with fine or medium foliage make dense, uniform hedges, while airy upright plants, like bamboo, can make a tropical-looking screen.
Dig a trench at least 2 feet deep and 3 feet wide, the desired length of your privacy screen. Amend the soil as necessary for the particular cultural requirements of the plants you select.
Drive wooden stakes into the ground at either end of the trench and tie a string between them. Use the string as a guide to lay out the shrubs at the proper spacing. Plant medium-sized evergreen shrubs 3 to 4 feet apart, space clumping bamboo 4 to 6 feet apart, and place conifers 6 feet apart in a single line.
Shape shrubs at planting time by pruning the branch tips. Prune back growth by one third in early spring for the next five growing seasons to create a bushy hedge. Make the tops of shrub hedges slightly narrower than the bases to allow light to reach the bottom branches.