Idaho Landscape Architect Examination
Advanced 100-Question Practice Exam
2026 | Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. Which site factor should be evaluated first when determining whether a
proposed landscape program is feasible?
A. Plant palette
B. Pavement color
C. Existing site constraints and opportunities
D. Furniture style
Answer: Existing site constraints and opportunities
Rationale: A professional site analysis begins with existing physical,
environmental, regulatory, and contextual conditions. These factors establish
the framework within which programming, grading, drainage, planting, and
circulation can be developed.
2. On a sloped site, which grading strategy generally provides the best
combination of accessibility, drainage control, and constructability?
,A. Maximize slope changes
B. Establish logical contours and minimize unnecessary earthwork
C. Eliminate all grade changes
D. Direct all drainage toward adjacent properties
Answer: Establish logical contours and minimize unnecessary earthwork
Rationale: Effective grading balances accessibility, drainage, cut-and-fill
quantities, retaining conditions, and constructability. Excessive manipulation
generally increases cost and environmental disturbance.
3. A proposed pedestrian route must overcome a significant elevation change
while maintaining accessibility. Which approach is most appropriate?
A. Use stairs exclusively
B. Provide an appropriately designed accessible route with compliant slopes and
landings
C. Increase the cross slope to shorten the route
D. Eliminate intermediate landings
Answer: Provide an appropriately designed accessible route with compliant
slopes and landings
Rationale: Accessible routes must be designed around applicable accessibility
requirements. Longitudinal slope, cross slope, landings, surface characteristics,
and transitions must all be coordinated.
4. What is the primary purpose of a contour line on a grading plan?
A. Show property ownership
B. Identify planting zones
C. Represent points of equal elevation
D. Identify utility locations
Answer: Represent points of equal elevation
,Rationale: Contours connect locations having the same elevation. Their spacing
and configuration communicate slope, drainage patterns, ridges, valleys, and
landform.
5. Two contour lines are extremely close together on a grading plan. What
does this normally indicate?
A. A relatively flat area
B. A steep slope
C. A drainage basin only
D. A property boundary
Answer: A steep slope
Rationale: Closely spaced contours indicate rapid elevation change over a short
horizontal distance, which corresponds to a steeper slope.
6. Which grading condition most clearly indicates a potential drainage
problem?
A. A continuous positive slope away from a building
B. A properly designed swale
C. A low point that has no defined outlet
D. A crowned pedestrian path
Answer: A low point that has no defined outlet
Rationale: A depression without an adequate drainage outlet can become a
ponding area. Low points should be intentionally designed with inlets, outlets,
infiltration systems, or other appropriate drainage measures.
7. A landscape architect is designing a bioswale. Which characteristic is most
important?
A. Impervious bottom with no vegetation
B. Conveyance and treatment of stormwater through an appropriately graded
vegetated system
, C. Maximum flow velocity
D. Elimination of all infiltration
Answer: Conveyance and treatment of stormwater through an appropriately
graded vegetated system
Rationale: Bioswales are designed to slow, convey, infiltrate, and often filter
stormwater. Their geometry, soils, vegetation, overflow provisions, and
maintenance requirements must work together.
8. Which soil characteristic most directly affects a plant's ability to obtain
oxygen at the root zone?
A. Soil color
B. Soil aeration and pore space
C. Surface texture alone
D. Mulch color
Answer: Soil aeration and pore space
Rationale: Roots require oxygen for respiration. Compaction and prolonged
saturation reduce air-filled pore space and can severely restrict root function.
9. What is the most appropriate reason for conducting a soil test before
specifying extensive planting?
A. To determine property ownership
B. To identify chemical and physical soil conditions affecting plant establishment
C. To determine the exact mature height of every plant
D. To eliminate the need for irrigation design
Answer: To identify chemical and physical soil conditions affecting plant
establishment
Rationale: Soil testing can identify pH, nutrient availability, salinity, texture, and
other conditions that influence plant selection and soil amendment strategies.
Advanced 100-Question Practice Exam
2026 | Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. Which site factor should be evaluated first when determining whether a
proposed landscape program is feasible?
A. Plant palette
B. Pavement color
C. Existing site constraints and opportunities
D. Furniture style
Answer: Existing site constraints and opportunities
Rationale: A professional site analysis begins with existing physical,
environmental, regulatory, and contextual conditions. These factors establish
the framework within which programming, grading, drainage, planting, and
circulation can be developed.
2. On a sloped site, which grading strategy generally provides the best
combination of accessibility, drainage control, and constructability?
,A. Maximize slope changes
B. Establish logical contours and minimize unnecessary earthwork
C. Eliminate all grade changes
D. Direct all drainage toward adjacent properties
Answer: Establish logical contours and minimize unnecessary earthwork
Rationale: Effective grading balances accessibility, drainage, cut-and-fill
quantities, retaining conditions, and constructability. Excessive manipulation
generally increases cost and environmental disturbance.
3. A proposed pedestrian route must overcome a significant elevation change
while maintaining accessibility. Which approach is most appropriate?
A. Use stairs exclusively
B. Provide an appropriately designed accessible route with compliant slopes and
landings
C. Increase the cross slope to shorten the route
D. Eliminate intermediate landings
Answer: Provide an appropriately designed accessible route with compliant
slopes and landings
Rationale: Accessible routes must be designed around applicable accessibility
requirements. Longitudinal slope, cross slope, landings, surface characteristics,
and transitions must all be coordinated.
4. What is the primary purpose of a contour line on a grading plan?
A. Show property ownership
B. Identify planting zones
C. Represent points of equal elevation
D. Identify utility locations
Answer: Represent points of equal elevation
,Rationale: Contours connect locations having the same elevation. Their spacing
and configuration communicate slope, drainage patterns, ridges, valleys, and
landform.
5. Two contour lines are extremely close together on a grading plan. What
does this normally indicate?
A. A relatively flat area
B. A steep slope
C. A drainage basin only
D. A property boundary
Answer: A steep slope
Rationale: Closely spaced contours indicate rapid elevation change over a short
horizontal distance, which corresponds to a steeper slope.
6. Which grading condition most clearly indicates a potential drainage
problem?
A. A continuous positive slope away from a building
B. A properly designed swale
C. A low point that has no defined outlet
D. A crowned pedestrian path
Answer: A low point that has no defined outlet
Rationale: A depression without an adequate drainage outlet can become a
ponding area. Low points should be intentionally designed with inlets, outlets,
infiltration systems, or other appropriate drainage measures.
7. A landscape architect is designing a bioswale. Which characteristic is most
important?
A. Impervious bottom with no vegetation
B. Conveyance and treatment of stormwater through an appropriately graded
vegetated system
, C. Maximum flow velocity
D. Elimination of all infiltration
Answer: Conveyance and treatment of stormwater through an appropriately
graded vegetated system
Rationale: Bioswales are designed to slow, convey, infiltrate, and often filter
stormwater. Their geometry, soils, vegetation, overflow provisions, and
maintenance requirements must work together.
8. Which soil characteristic most directly affects a plant's ability to obtain
oxygen at the root zone?
A. Soil color
B. Soil aeration and pore space
C. Surface texture alone
D. Mulch color
Answer: Soil aeration and pore space
Rationale: Roots require oxygen for respiration. Compaction and prolonged
saturation reduce air-filled pore space and can severely restrict root function.
9. What is the most appropriate reason for conducting a soil test before
specifying extensive planting?
A. To determine property ownership
B. To identify chemical and physical soil conditions affecting plant establishment
C. To determine the exact mature height of every plant
D. To eliminate the need for irrigation design
Answer: To identify chemical and physical soil conditions affecting plant
establishment
Rationale: Soil testing can identify pH, nutrient availability, salinity, texture, and
other conditions that influence plant selection and soil amendment strategies.
