Mixing Up Screening Borders

Does your neighbor remind you more of Sanford and Son than Mr. and Mrs. Tidy across the street?  Maybe the sound or light of passing cars keeps you awake at night.  Do you want to separate your garden into different landscape areas?  You may be in need of some landscape screening.  There are many different ways to use plants to achieve these goals.

Let’s go ahead and get past the idea of using a straight row of Leyland cypress as a form of screening (monoculture).  That is a bad idea for a number of different reasons, most importantly being that Leyland cypress has many major pathogens that seem to be damaging and killing Leylands across the southeast (not to mention insect issues).  In fact, it is not a very good idea to use one particular plant of any species in large numbers for screening purposes.  Why is that?  Plants intended for visual barriers are usually planted closely together, or close enough so that they will grow into one-another.  These plants are often genetically similar or even identical.  This spells disaster when insects or diseases adapt to the over-abundance of food or host plant material, particularly when plants are planted close together.  The closer the plants are planted, the shorter the distance a pest or disease has to travel for its next meal.  A domino effect of damaged or dead trees or shrubs can soon follow.  This is not to say that the same plant can not be planted beside itself in the landscape.  Groupings of three, five, or seven of the same species are usually fine.

If we can not use large numbers of one species, how can we create screening borders?  The best horticultural answer is actually pretty easy.  Mix it up!  By using several different plant species in one border, we are increasing genetic diversity and scrapping the monoculture that occurs when one species is planted in mass by itself.  Not only will we have a healthier landscape by using different plants, we will also gain interest by mixing textures, forms, and using contrasting colors.  Mixed screening borders also serve as great habitat for birds and other wildlife.

There is a long list of plants that can be utilized for screening purposes.  The most popular choice at Fairview is the green giant arborvitae (Thuja plicata ‘Green Giant’).  Its fast growth rate, columnar form, and dark green foliage make ‘Green Giant’ a great choice for screening.  This plant is a great substitute for leyland cypress due to its nearly identical size, form and growth rate, without the pest and disease issues.  ‘Green Giant’ can reach heights of 40’+ and widths of 6-8’, and is a wonderful lustrous dark green in the warm months and develops a unique bronze look in the winter.  Along the same lines of ‘Green Giant’ is the ‘Yoshino’ Japanese cedar (Cryptomeria japonica ‘Yoshino’).  This is one of my personal favorite screening plants due to its regal form, changing colors, and excellent texture.  ‘Yoshino’ is a pyramidal upright plant in its juvenile state that seems to begin to form cascading branches as it matures and gains height.  New growth in spring is light green, maturing to dark green in the summer months, and bronzing during winter.  It seems to have a finer texture in the landscape when compared to other upright conifers.

Combining these conifers with broad leaf evergreen shrubs adds great texture contrast and depth to the landscape.  Chindo viburnum (Viburnum awabuki ‘Chindo’) is a great choice to be mixed with conifers in the garden.  ‘Chindo’ viburnum is an upright rounded to pyramidal shaped shrub with large glossy green leaves achieving heights of 18’+ and widths of 8’.  With age, this plant will have clusters of small white flowers which will produce pendulous chains of red berries in the fall and winter months.  The coarse texture of ‘Chindo’ combines well with other finer textured plants.  Nellie Stevens holly (Ilex x ‘Nellie R. Stevens’) is another popular choice for screening.  Nellie Stevens holly is a vigorous upright grower to 20’+ in height.  Like many other hollies, it produces red berry clusters in the fall.  It is important to note that most Nellies seen in commercial landscapes are routinely sheared to be maintained in a short, dense form.  If left to Mother Nature, Nellie Stevens holly will have a much taller, almost columnar form.

If a screen of 20’ or larger is a little to big for a specific area, try using plants in the 10’ range.  Zhuzhou loropetalum (Loropetalum chinense var. rubrum ‘Zhuzhou Fuchsia’) will add quite a bit of interest to any screening border.  There are many cultivars of loropetalum available, the most popular of which have purple foliage and frilly, strap-like pink flowers.  ‘Zhuzhou’ is one of the larger forms, attaining heights of 10’ and widths of 8’.  This large, rounded, intense purple shrub will add a splash of color in any border.  The small diameter of the branches makes this plant move quite a bit with the wind. 

These are only a few of the many screening plants available.  It is important to note that privacy borders do not have to be constituted of only large evergreen shrubs.  Any plants from large deciduous trees to perennials and annuals can be incorporated into the screening border for year-round appeal.  If you want to refrain from erecting a fence along your property line, consider using some of these plants for screening. 

Happy Planting!
Brad Rollins