CSLB C-27 Landscaping ContractorPlanting and LandscapingHard
A landscape client requests a hedge that will provide year-round privacy and has a very uniform, formal appearance. They are concerned about invasive roots impacting nearby structures. Which of the following plant selections is best suited for this application in a California climate zone 9b?
- AFicus microcarpa 'Nitida' (Indian Laurel Fig)
- BPittosporum tenuifolium (Kohuhu)
- CLigustrum japonicum (Japanese Privet)
- DElaeagnus pungens (Silverthorn)
Show answer & explanationAnswer & explanation
Correct answer: B. Pittosporum tenuifolium (Kohuhu)
Pittosporum tenuifolium (Kohuhu) is an excellent choice for a formal, evergreen hedge in California. It tolerates shearing well, maintains a dense, uniform appearance, and has a relatively non-invasive root system compared to the other options. Ficus microcarpa 'Nitida' is notorious for invasive roots, Ligustrum japonicum can be invasive and has aggressive roots, and Elaeagnus pungens has thorny branches and a less formal growth habit.
Why the other options are wrong
- A. Ficus microcarpa 'Nitida' is known for its highly aggressive and invasive root system that can damage foundations, sidewalks, and plumbing.
- C. Ligustrum japonicum can be an invasive species in California and also has a strong root system that can become problematic, though generally less destructive than Ficus.
- D. Elaeagnus pungens has sharp thorns and a more informal, sprawling growth habit, making it less suitable for a 'very uniform, formal' hedge, and its roots can be robust.
Formal Evergreen Hedge Selection
Choosing appropriate evergreen plant species for creating dense, uniform hedges that provide privacy and tolerate shearing, while considering factors like root invasiveness and climate suitability.
- Requires evergreen foliage for year-round privacy.
- Must tolerate frequent shearing for formal shape.
- Root system should be non-invasive near structures.
- Climate zone compatibility is essential.
Memory trick: Hedge Harmony: Form, Roots, Zone – all in sync!