Master Gardener Exam Questions and
Answers Plus Rationales
1. Which soil type is best for most garden vegetables?
a) Clay
b) Sand
c) Loam
d) Silt
Loam has a balanced mixture of sand, silt, and clay, providing
good drainage and nutrient retention.
2. What is the primary purpose of mulch in a garden?
a) Attract insects
b) Retain soil moisture and suppress weeds
c) Increase soil acidity
d) Provide nitrogen
Mulch helps conserve water, suppress weeds, and regulate soil
temperature.
3. Which part of the plant conducts photosynthesis?
a) Root
b) Stem
c) Leaf
d) Flower
Leaves contain chlorophyll, which captures sunlight for
photosynthesis.
,4. Which nutrient is essential for strong root development?
a) Nitrogen
b) Phosphorus
c) Potassium
d) Calcium
b) Phosphorus
Phosphorus promotes root growth and flower/fruit development.
5. What is the ideal pH range for most garden soils?
a) 4.5–5.5
b) 5.0–6.0
c) 6.0–7.0
d) 7.5–8.5
Most vegetables grow best in slightly acidic to neutral soils.
6. Companion planting of basil near tomatoes can:
a) Inhibit tomato growth
b) Repel pests
c) Reduce soil nutrients
d) Increase leaf diseases
Basil can repel certain insects that commonly attack tomatoes.
7. Which of the following is a cool-season crop?
a) Corn
b) Beans
c) Lettuce
d) Peppers
Lettuce grows best in cooler temperatures and can bolt in heat.
8. What is the best method to propagate plants like coleus or basil?
a) Seeds
, b) Cuttings
c) Grafting
d) Layering
Many herbs root easily from stem cuttings.
9. What does the term “hardiness zone” refer to?
a) Soil type
b) Rainfall levels
c) Minimum winter temperatures for plant survival
d) Day length requirements
USDA hardiness zones indicate which plants can survive local
winter lows.
10. Which practice helps prevent fungal diseases in plants?
a) Frequent overhead watering
b) Crowding plants
c) Proper spacing and watering at the base
d) Ignoring pruning
Watering at the soil level and spacing plants improves air
circulation and reduces disease.
11. What is the main function of nitrogen in plants?
a) Root growth
b) Leaf and stem growth
c) Flower production
d) Disease resistance
Nitrogen is a key component of chlorophyll and promotes
vegetative growth.
12. Which tool is best for pruning small branches?
a) Shovel
, b) Hand pruners
c) Trowel
d) Hoe
Hand pruners allow precise cutting of small branches without
damaging the plant.
13. What is the main advantage of raised beds?
a) Increased shade
b) Improved drainage and soil quality
c) Reduced sun exposure
d) Easier weed growth
Raised beds warm up faster, drain better, and allow soil
amendments.
14. Which of the following plants is a legume that can fix
nitrogen in soil?
a) Tomato
b) Lettuce
c) Pea
d) Cabbage
Legumes host Rhizobium bacteria in root nodules, which convert
atmospheric nitrogen to usable forms.
15. Which gardening practice reduces soil compaction?
a) Frequent tilling
b) Walking on beds
c) Using raised beds or paths
d) Adding sand only
Designated paths and raised beds reduce foot traffic on planting
areas.
Answers Plus Rationales
1. Which soil type is best for most garden vegetables?
a) Clay
b) Sand
c) Loam
d) Silt
Loam has a balanced mixture of sand, silt, and clay, providing
good drainage and nutrient retention.
2. What is the primary purpose of mulch in a garden?
a) Attract insects
b) Retain soil moisture and suppress weeds
c) Increase soil acidity
d) Provide nitrogen
Mulch helps conserve water, suppress weeds, and regulate soil
temperature.
3. Which part of the plant conducts photosynthesis?
a) Root
b) Stem
c) Leaf
d) Flower
Leaves contain chlorophyll, which captures sunlight for
photosynthesis.
,4. Which nutrient is essential for strong root development?
a) Nitrogen
b) Phosphorus
c) Potassium
d) Calcium
b) Phosphorus
Phosphorus promotes root growth and flower/fruit development.
5. What is the ideal pH range for most garden soils?
a) 4.5–5.5
b) 5.0–6.0
c) 6.0–7.0
d) 7.5–8.5
Most vegetables grow best in slightly acidic to neutral soils.
6. Companion planting of basil near tomatoes can:
a) Inhibit tomato growth
b) Repel pests
c) Reduce soil nutrients
d) Increase leaf diseases
Basil can repel certain insects that commonly attack tomatoes.
7. Which of the following is a cool-season crop?
a) Corn
b) Beans
c) Lettuce
d) Peppers
Lettuce grows best in cooler temperatures and can bolt in heat.
8. What is the best method to propagate plants like coleus or basil?
a) Seeds
, b) Cuttings
c) Grafting
d) Layering
Many herbs root easily from stem cuttings.
9. What does the term “hardiness zone” refer to?
a) Soil type
b) Rainfall levels
c) Minimum winter temperatures for plant survival
d) Day length requirements
USDA hardiness zones indicate which plants can survive local
winter lows.
10. Which practice helps prevent fungal diseases in plants?
a) Frequent overhead watering
b) Crowding plants
c) Proper spacing and watering at the base
d) Ignoring pruning
Watering at the soil level and spacing plants improves air
circulation and reduces disease.
11. What is the main function of nitrogen in plants?
a) Root growth
b) Leaf and stem growth
c) Flower production
d) Disease resistance
Nitrogen is a key component of chlorophyll and promotes
vegetative growth.
12. Which tool is best for pruning small branches?
a) Shovel
, b) Hand pruners
c) Trowel
d) Hoe
Hand pruners allow precise cutting of small branches without
damaging the plant.
13. What is the main advantage of raised beds?
a) Increased shade
b) Improved drainage and soil quality
c) Reduced sun exposure
d) Easier weed growth
Raised beds warm up faster, drain better, and allow soil
amendments.
14. Which of the following plants is a legume that can fix
nitrogen in soil?
a) Tomato
b) Lettuce
c) Pea
d) Cabbage
Legumes host Rhizobium bacteria in root nodules, which convert
atmospheric nitrogen to usable forms.
15. Which gardening practice reduces soil compaction?
a) Frequent tilling
b) Walking on beds
c) Using raised beds or paths
d) Adding sand only
Designated paths and raised beds reduce foot traffic on planting
areas.
