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NYC Administrative Horticulturist exam COMPLETE
QUESTIONS AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
summarized Exam Coverage
The NYC Administrative Horticulturist exam tests: educating and interacting with the public on
horticultural topics; familiarity with a wide range of plant species including trees, shrubs, perennials,
annuals, and aquatic plants; principles and practices of planting, cultivating, pruning, propagating, and
maintaining landscapes; pest and disease identification and control; soil science and fertility
management; irrigation systems and water conservation; and seasonal landscape maintenance including
snow/ice control .
1. You are conducting a public workshop on rose care. A participant asks about small black spots with
fringed margins on the leaves. What is the most likely disease and its cause?
A) Rust caused by fungal spores
B) Black spot caused by Diplocarpon rosae
C) Powdery mildew caused by dry conditions
D) Botrytis blight caused by excess humidity
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Answer: B
Black spot (Diplocarpon rosae) produces circular black spots with fringed or feathery margins on rose
leaves, leading to defoliation if untreated .
2. What is the ideal soil pH range for most turfgrasses grown in New York State?
A) 4.5–5.5
B) 5.5–6.0
C) 6.0–7.0
D) 7.5–8.5
Answer: C
Most turfgrasses perform best in slightly acidic to neutral soils (6.0–7.0), which optimizes nutrient
availability for root uptake .
3. Which of the following plants is considered invasive in New York State and should not be
recommended for public plantings?
A) Red Maple (Acer rubrum)
B) Sugar Maple (Acer saccharum)
C) Japanese Barberry (Berberis thunbergii)
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D) Eastern Redbud (Cercis canadensis)
Answer: C
Japanese barberry is an aggressive invasive shrub that alters soil pH and harbors ticks, making it
unsuitable for public landscapes .
4. A resident brings a plant sample with yellowing between the leaf veins while the veins themselves
remain green. What nutrient deficiency is most likely?
A) Nitrogen deficiency
B) Phosphorus deficiency
C) Potassium deficiency
D) Iron deficiency
Answer: D
Interveinal chlorosis is a classic sign of iron deficiency, especially common in alkaline soils where iron
becomes unavailable .
5. Which pest is known for tunneling inside the trunks and branches of ash trees, causing dieback and
tree mortality?
A) Aphids
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B) Leafhoppers
C) Emerald Ash Borer (Agrilus planipennis)
D) Whiteflies
Answer: C
Emerald Ash Borer larvae bore into the wood of ash trees, disrupting vascular flow and ultimately killing
the tree within a few years .
6. What is the best time of year to plant most perennials in New York to ensure successful
establishment?
A) Mid-winter when the ground is frozen
B) Spring or early fall when temperatures are moderate
C) Late summer during the hottest period
D) Early winter just before snowfall
Answer: B
Spring and early fall allow plants to establish root systems before extreme summer heat or winter cold
stress occurs .
NYC Administrative Horticulturist exam COMPLETE
QUESTIONS AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
summarized Exam Coverage
The NYC Administrative Horticulturist exam tests: educating and interacting with the public on
horticultural topics; familiarity with a wide range of plant species including trees, shrubs, perennials,
annuals, and aquatic plants; principles and practices of planting, cultivating, pruning, propagating, and
maintaining landscapes; pest and disease identification and control; soil science and fertility
management; irrigation systems and water conservation; and seasonal landscape maintenance including
snow/ice control .
1. You are conducting a public workshop on rose care. A participant asks about small black spots with
fringed margins on the leaves. What is the most likely disease and its cause?
A) Rust caused by fungal spores
B) Black spot caused by Diplocarpon rosae
C) Powdery mildew caused by dry conditions
D) Botrytis blight caused by excess humidity
, Page 2 of 126
Answer: B
Black spot (Diplocarpon rosae) produces circular black spots with fringed or feathery margins on rose
leaves, leading to defoliation if untreated .
2. What is the ideal soil pH range for most turfgrasses grown in New York State?
A) 4.5–5.5
B) 5.5–6.0
C) 6.0–7.0
D) 7.5–8.5
Answer: C
Most turfgrasses perform best in slightly acidic to neutral soils (6.0–7.0), which optimizes nutrient
availability for root uptake .
3. Which of the following plants is considered invasive in New York State and should not be
recommended for public plantings?
A) Red Maple (Acer rubrum)
B) Sugar Maple (Acer saccharum)
C) Japanese Barberry (Berberis thunbergii)
, Page 3 of 126
D) Eastern Redbud (Cercis canadensis)
Answer: C
Japanese barberry is an aggressive invasive shrub that alters soil pH and harbors ticks, making it
unsuitable for public landscapes .
4. A resident brings a plant sample with yellowing between the leaf veins while the veins themselves
remain green. What nutrient deficiency is most likely?
A) Nitrogen deficiency
B) Phosphorus deficiency
C) Potassium deficiency
D) Iron deficiency
Answer: D
Interveinal chlorosis is a classic sign of iron deficiency, especially common in alkaline soils where iron
becomes unavailable .
5. Which pest is known for tunneling inside the trunks and branches of ash trees, causing dieback and
tree mortality?
A) Aphids
, Page 4 of 126
B) Leafhoppers
C) Emerald Ash Borer (Agrilus planipennis)
D) Whiteflies
Answer: C
Emerald Ash Borer larvae bore into the wood of ash trees, disrupting vascular flow and ultimately killing
the tree within a few years .
6. What is the best time of year to plant most perennials in New York to ensure successful
establishment?
A) Mid-winter when the ground is frozen
B) Spring or early fall when temperatures are moderate
C) Late summer during the hottest period
D) Early winter just before snowfall
Answer: B
Spring and early fall allow plants to establish root systems before extreme summer heat or winter cold
stress occurs .
