What Experienced Landscape Architect’s Need To Know To Pass The California Supplemental Exam
Most landscape architect candidates who take the California Supplemental Exam for landscape architects are seeking their first license. However, experienced landscape architects who are licensed in another state seep reciprocal registration (reciprocity) in California. Experienced landscape architects have a wealth of experience and only need to know the exam information that pertains specifically to California plants, licensing laws, and state agencies.
Here is a short list of topics that can speed up the exam preparation process.
- California state agencies
- California native plants
- Toxic plants to avoid
- California green building code (CALGreen)
- California Model Water Efficient Landscape Ordinance

California State Agencies
California’s complex regulatory system involves overlapping jurisdictions from several state agencies. These are the most important agin vies to know for the California Supplemental Exam.
California Department of Fish and Wildlife
This agency, formerly known as the California Department of Fish and Game, is responsible for protecting threatened and endangered species. Since California has a high rate of endemic species, the agency regulates development activity on many sites. For the exam, know the permit process for sites that have special status species. HINT: CEQA is important.
California Geologic Survey
This agency produces landslide hazard maps, among other useful resources. These resources compliment FEMA flood hazard maps and other geologic resources available from the US Geologic Survey.
Division Of State Architect
The Division of the State Architect is responsible for promulgating state accessibility requirements. Some state accessibility standards are more detailed or restrictive than the best practices published by the US Department of Justice.
California Coastal Commission
No other state has an organization that wields so much power for development projects along the coast as the California Coastal Commission. For the California Supplemental Exam, know the basic restrictions on coastal development and understand the permitting process.
California Department of Food and Agriculture
This state agency is responsible for managing the state’s noxious weed program and instituting plant quarantines (which occasionally disrupts the nursery industry and plant availability).
Regional Water Quality Control Boards
Nine regional water quality control boards manage the state’s watersheds and administer the federal Clean Water Act. This is the agency lat issues land disturbance permits for large-scale grading.
Native Plants
Native plants and planting-related questions are a significant part of the exam. It is imperative that you know the most common native plants and how to use them in the landscape.
Useful Free Resources
Tree of Life Nursery — Their great website and on-line catalog are a great resource for landscape architects. If you get the chance, visit their beautifully landscaped growing grounds.
Las Pilitas Nursery — You will find many well-written articles about common native plants that are available to landscape architects.
Theodore Payne Foundation — This non-profit organization advocates using California native plants in gardens and landscapes. Their website has lists of plants to use in specific landscape situations.
Major Genera to Know for the CSE
- Quercus — native oak trees are a huge subject area on the exam
- Ceanothus — California lilac
- Actostaphllos — Manzanita
- Ribes — Currants and Gooseberries
- Eriogonum — Buckwheat
- Salvia — Sage (know the key native species)
- Mimulus (synonym: Diplacus) — native monkey flowers
- Heteromeles arbutifolia — Toyon or California Holly
Poisonous Plants
Surprisingly, many common landscape plants are extremely toxic to people and domestic animals. Oleander (Nerium oleander) is the most toxic common landscape plant used in California gardens. A few leaves can kill children and livestock. Know that oleander should never be planted in school grounds, daycare facilities, and along horse trails.
California Green Building Code (CALGreen)
CALGreen is being adopted by local municipalities as the new “law of the land”. While each permitting authority can pick and choose which standards in the code they want for their municipality, there are common themes that affect all landscape architects in the state.
CALGreen has two tiers of compliance. Tier 1 is the minimum standard for sustainable development in the new code. Landscape architects need to be concerned with CALGreen’s site grading guidelines, water-conserving irrigation technologies, native or adapted plant selection, and turf restrictions. Tier 2 includes more energy and water conservation standards.
Model Water Efficient Landscape Ordinance
This model ordinance is also adopted by local municipalities. This ordinance regulates the total amount of irrigation water a site can use. Know how the evapotranspiration rate and plant water use factors affect the water use calculations. For more information on the Model Water Efficient Landscape Ordinance, check out this article.
Final Thoughts
Landscape architects who are licensed in another state can use their prior experience and common sense to answer many questions on the exam. Focus on the California-specific topics on the exam and you should be able to pass the California Supplemental Exam.

