Certified Professional Horticulturist (CPH) Practice Exam

Which of the following should you consider when selecting a tree for screening purposes?

1. Fall foliage color

2. Nutrient requirements

3. Growth habit

4. Type of root system

The correct answer is: Growth habit

When selecting a tree for screening purposes, the growth habit is a crucial factor to consider. The growth habit describes the shape and structure of the tree as it matures, which directly impacts its ability to provide effective screening or privacy. Trees with a dense, upright, or broad spreading growth habit are often preferred because they create a solid visual barrier, blocking unwanted views and noise. For example, species that naturally develop a thick canopy or have closely spaced branches are better suited for screening than those with a sparse or irregular growth habit. This characteristic also influences how closely trees can be planted together to create a continuous screen, making it essential for landscape design focused on privacy. In contrast, while factors such as fall foliage color, nutrient requirements, and type of root system are also important in overall tree selection, they do not directly influence the tree’s ability to serve as an effective screen. Fall color may enhance aesthetic appeal but is not critical for screening purposes. Nutrient needs and root systems are relevant for maintenance and health of the tree but do not affect the tree's screening capacity in terms of density and structure.