CLARB Planting Design and Ecology 2

Question 1

A designer specifies Quercus palustris (pin oak) for a parking lot island. What soil pH concern should be noted?

Accepted Answer

Pin oak is susceptible to iron chlorosis in high pH (alkaline) soils common near concrete

Answer

Pin oak develops interveinal chlorosis when planted in alkaline soils (pH above 7.0) because iron becomes unavailable, making it a poor choice near concrete curbs.

Question 2

What is allelopathy in the context of planting design?

Accepted Answer

The chemical inhibition of growth in neighboring plants by compounds released from certain species

Answer

Allelopathy occurs when a plant releases biochemicals that inhibit germination or growth of other plants nearby, such as black walnut (Juglans nigra) producing juglone.

Question 3

Which planting design principle ensures that plants provide multi-season interest across spring, summer, fall, and winter?

Accepted Answer

Sequential or year-round interest through selection of plants with overlapping seasonal features

Answer

Selecting plants with varied bloom times, fall color, fruit, bark texture, and winter structure ensures the landscape remains visually engaging throughout the year.

Question 4

What minimum clear trunk height is typically specified for street trees to provide clearance for pedestrians?

Accepted Answer

8 feet minimum clearance over pedestrian paths

Answer

Street trees are typically pruned or trained to maintain at least 8 feet of clear trunk height over sidewalks to ensure safe pedestrian passage.

Question 5

A planting plan calls for 'native species only.' Which of the following best describes a native plant in the US context?

Accepted Answer

A species that occurred naturally in a region prior to European colonization

Answer

Native plants are those that evolved and existed in a specific region before European settlement, forming ecological relationships with local wildlife and soil organisms.

CLARB - Council of Landscape Architectural Registration Boards Practice Test

CLARB - Council of Landscape Architectural Registration Boards Practice Test

CLARB Planting Design and Ecology 2