LARE LARE Plants and Planting Design 2 — Questions and Answers
Question 1: What is 'allelopathy' and how does it affect planting design?
- A soil amendment strategy that improves plant uptake
- The release of chemicals by a plant that inhibit growth of nearby plants (Correct answer)
- A method of spacing plants to reduce disease
- The use of companion planting to attract pollinators
Correct answer: The release of chemicals by a plant that inhibit growth of nearby plants
Allelopathy occurs when a plant releases biochemicals that suppress the germination or growth of neighboring plants, which must be accounted for in planting plans.
Question 2: Which term describes the practice of grouping plants with similar water needs together to improve irrigation efficiency?
- Xeriscape zoning
- Hydrozoning (Correct answer)
- Microclimate clustering
- Water budgeting
Correct answer: Hydrozoning
Hydrozoning groups plants with similar water requirements into the same irrigation zones, reducing water waste and improving plant health.
Question 3: On a LARE exam question, which factor is MOST critical when selecting street trees for a narrow tree pit in an urban streetscape?
- Flower color and ornamental value
- Tolerance of compacted, poorly drained soils and limited rooting volume (Correct answer)
- Rapid growth rate to achieve canopy closure quickly
- Low leaf litter production to reduce maintenance
Correct answer: Tolerance of compacted, poorly drained soils and limited rooting volume
Urban street trees face severe rooting restrictions, compaction, and poor drainage, so stress tolerance is the primary selection criterion for survival.
Question 4: What does a 'plant schedule' on construction documents typically include?
- Only the common names and quantities of plants
- Botanical name, common name, size, quantity, and special conditions (Correct answer)
- Planting dates and seasonal installation sequence only
- Budget cost per plant unit
Correct answer: Botanical name, common name, size, quantity, and special conditions
A plant schedule is a tabular legend on planting plans listing each plant's botanical and common name, specified size, quantity, and any special installation requirements.
Question 5: Which planting design principle recommends using odd numbers of plants in groupings to create a more naturalistic appearance?
- Rhythm and repetition
- The rule of odd numbers (Correct answer)
- Mass planting theory
- Focal point hierarchy
Correct answer: The rule of odd numbers
The rule of odd numbers holds that groupings of 3, 5, or 7 plants appear more natural and visually balanced than even-numbered groupings.
Question 6: In a LARE planting plan, what does the symbol 'DBH' refer to?
- Design Build Height — the expected height at five years
- Diameter at Breast Height — trunk diameter measured at 4.5 feet above grade (Correct answer)
- Depth Below Hardpan — used to specify root barrier installation
- Design Base Height — the minimum clearance under a tree canopy
Correct answer: Diameter at Breast Height — trunk diameter measured at 4.5 feet above grade
DBH (Diameter at Breast Height) is the standard forestry measurement of trunk diameter taken at 4.5 feet above ground, used to describe existing trees.
LARE LARE Plants and Planting Design 2
What is 'allelopathy' and how does it affect planting design?