There are a large number of plants that will work well as a screen to block an unwanted view. A number of design methods are also employed when planting a screen as a visual block or to create interest. I will discuss some of my beliefs as a professional in the industry for more than 20 years.
In planning and planting a screen, either evergreen or deciduous plants can be used. Some common evergreen plants used in our area are Leyland Cypress, Eastern Red Cedar, Green Giant Arborvitae, Emerald Arborvitae, and Cherry Laurel. Some deciduous trees are also employed such as Redbud, Cherry, Serviceberry, and Pear. Leyland cypress can make a nice screen, but are now threatened by a canker that can jeopardize the longevity of the plant, thus jeopardizing your screen. Eastern Red Cedar is a native that looks great, but can be tough to propagate and transplant. The success rate is normally low for digging these plants and trying to move them. That leads us to Green Giant Arborvitae, Emerald Arborvitae and Cherry Laurel. These three are very durable in our area. They grow relatively fast, require little water once established, and do not face many issues with diseases or pests. Granted the Arborvitae do get bagworms in the late summer, they are easy to spot and remove or treat. As for the deciduous plants, they are all fairly tough and care is easy. Some of the softer woods like pear and cherry can be prone to webworms, but once again, they are easily spotted and easily treated. The list of deciduous trees that can be used for screen plants goes on and on, but it’s always safe to stick with natives.
For years, it has been common practice to plant a row of the same tree, like little soldiers, in a line down the property line or near the area you are trying to screen. In my experience, and based on the opinions of countless other professionals, a mixed/ natural screen is the most logical, if it’s an option. Using a wide array of plants of different sizes and characteristics creates an interesting screen. The largest benefit to this, besides the natural look, is that if one dies, you are not searching for an exact match. For example, if you plant a row of Emerald Arborvitae, use 20 plants that are 5 feet tall at the time, it’s a costly project. Just imagine if you wait 7 or 8 years, then one or two die. Replacing that plant, which now is around 10 feet tall or better, is going to be a lot more costly. You endure the cost of having the dead removed, then planting new ones. With a mixed border, if one dies, you can simply cut down the dead, and plant another plant of any size somewhere nearby. The missing plant is not as noticeable when working with a mixed screen. Another benefit is you get the year round privacy from the evergreens, but in spring you can throw in a mix that allows for some flowering at different times of the year. Throw in some redbuds, cherries, crape myrtles, and witch hazel for flowering from March until November or December. When the evergreen trees are mixed in the background of the deciduous trees, the flowers and fall color really pop too.