Texas Master Gardener Certification Exam COMPLETE EXAM
QUESTIONS AND VERIFIED ANSWERS | 2026–2027 LATEST
UPDATE | GUARANTEED PASS | DETAILED RATIONALES | FULL
STUDY GUIDE | EXAM PREP | PRACTICE TEST |
CERTIFICATION PREPARATION
1. A homeowner in Central Texas notices their St. Augustine lawn is developing irregular yellow
patches despite regular watering. Upon closer inspection, the blades pull away easily from the
runners. What is the most likely cause?
A. Chinch bug infestation
B. Brown patch fungus
C. Iron chlorosis
D. Over-fertilization with nitrogen
Correct Answer: A. Chinch bug infestation
Rationale: Chinch bugs are a common pest of St. Augustine grass in Texas. They feed by piercing the
grass blades and sucking sap, which causes yellowing and death, and the damaged leaf blades will
easily pull away from the runners. Brown patch fungus typically presents as circular, brownish
patches rather than irregular yellowing, and the grass does not pull away easily. Iron chlorosis causes
yellowing but is usually uniform across the lawn and doesn't affect the blade's attachment to the
runner. Over-fertilization with nitrogen would cause excessive growth and could lead to thatch
buildup, not the specific symptom of blades pulling away.
2. What is the most critical component of Integrated Pest Management (IPM) that should be
implemented first in a Texas landscape?
A. Application of broad-spectrum insecticides
B. Monitoring and correct identification of pests
C. Planting only native species
D. Immediate removal of all affected plants
Correct Answer: B. Monitoring and correct identification of pests
Rationale: The first and most crucial step in IPM is identifying the pest correctly and monitoring its
population. Without proper identification, you cannot determine the best management strategy,
which could be cultural, mechanical, biological, or, as a last resort, chemical. Blindly applying
insecticides (Option A) is a common mistake and works against IPM principles. Planting only natives
(Option C) helps with ecosystem health but is not the first step in IPM; it is a preventative strategy.
Removal (Option D) is a last-resort measure, not the first step.
3. A soil test from a new vegetable garden in East Texas shows a pH of 5.2. What is the most
appropriate amendment to apply, and what is the recommended timeframe for best results?
,A. Apply agricultural lime immediately before planting; it takes effect in two to three weeks.
B. Apply sulfur several months before planting.
C. Apply agricultural lime several months before planting to allow it to react with the soil.
D. No amendment is needed; most vegetables prefer acidic soil.
Correct Answer: C. Apply agricultural lime several months before planting to allow it to react with
the soil.
Rationale: A pH of 5.2 is acidic. The ideal pH for most vegetables is between 6.0 and 7.0 . To raise the
pH, agricultural lime (calcium carbonate) is the standard amendment. The key is that lime reacts
slowly with the soil; it can take several months to see a significant change, so it should be applied
well in advance of planting. Sulfur is used to lower pH. While some plants like blueberries love acidic
soil, most vegetables prefer a more neutral range.
4. In the Texas Master Gardener handbook, the term "Earth-Kind" landscaping is a foundational
concept. What is the primary goal of this approach?
A. To create a landscape that requires no supplemental water
B. To use only native Texas plants in the landscape design
C. To promote environmentally responsible landscaping that conserves water and reduces chemical
use
D. To achieve a traditional, high-maintenance lawn with a manicured appearance
Correct Answer: C. To promote environmentally responsible landscaping that conserves water and
reduces chemical use.
Rationale: The Earth-Kind Landscaping system, developed by Texas A&M AgriLife Extension, uses
research-proven techniques to create beautiful, sustainable landscapes. It focuses on reducing water
use, fertilizer, and pesticide application while still allowing for a wide selection of plants that are
adapted to Texas conditions. The goal is not to require no water (Option A) but rather to use it
efficiently. It also encourages using adapted plants, not exclusively natives (Option B). High-
maintenance lawns (Option D) are the antithesis of the Earth-Kind philosophy.
5. A Master Gardener is advising a homeowner on the proper way to water their lawn. Which of
the following is the most water-efficient irrigation method for a new shrub border?
A. Overhead sprinklers that apply water quickly in a 15-minute cycle
B. A soaker hose placed under a layer of mulch
C. A drip irrigation system with emitters at the base of each plant
D. Frequent hand watering to keep the soil surface moist
Correct Answer: C. A drip irrigation system with emitters at the base of each plant
Rationale: Drip irrigation is the most efficient method because it delivers water directly to the plant's
root zone, minimizing evaporation and runoff . A soaker hose (Option B) is also efficient for beds but
can be less precise and more suited for row crops or mass plantings. Overhead sprinklers (Option A)
are prone to high water loss from evaporation and wind drift. Frequent hand watering (Option D) is
often inefficient and can lead to shallow root systems.
,6. A gardener is preparing their vegetable bed and reads on a fertilizer bag "10-20-10." What does
the number "20" represent?
A. The percentage of Nitrogen (N) in the mix
B. The percentage of Phosphorus (P₂O₅) in the mix
C. The percentage of Potassium (K₂O) in the mix
D. The amount of trace minerals in the fertilizer
Correct Answer: B. The percentage of Phosphorus (P₂O₅) in the mix
Rationale: The three numbers on a fertilizer bag represent the N-P-K ratio (Nitrogen, Phosphorus,
Potassium) in that specific order. Therefore, 10-20-10 means the fertilizer contains 10% Nitrogen, 20%
Phosphorus (as P₂O₅), and 10% Potassium (as K₂O) . Phosphorus is crucial for root development and
flowering.
7. You are helping a community garden choose a mulch for their vegetable beds. What is the most
significant benefit of applying a 2- to 3-inch layer of organic mulch like shredded leaves or pine
bark?
A. It significantly raises the soil's pH over time.
B. It adds large amounts of nitrogen to the soil.
C. It conserves soil moisture, suppresses weeds, and moderates soil temperature.
D. It provides a habitat for beneficial insects, which reduces pest populations.
Correct Answer: C. It conserves soil moisture, suppresses weeds, and moderates soil temperature.
Rationale: The primary functional benefits of mulching are water conservation (reducing
evaporation), weed suppression (blocking sunlight to weed seeds), and moderating soil
temperatures. While organic mulches do add some organic matter to the soil as they decompose,
they are not a significant source of nitrogen (Option B) and do not raise the soil pH (Option A). While
they can provide habitat for some beneficial insects, this is a secondary benefit, not the primary
function (Option D).
8. A homeowner in the Hill Country wants to plant a drought-tolerant ornamental tree. Which tree
is not well-suited to Texas conditions and would likely suffer from high water needs and iron
chlorosis?
A. Texas Redbud
B. Cedar Elm
C. Southern Magnolia
D. Live Oak
Correct Answer: C. Southern Magnolia
Rationale: While the Southern Magnolia is a beautiful tree, it is not as drought-tolerant as the Texas
Redbud, Cedar Elm, or Live Oak. It prefers moist, well-drained, slightly acidic soils. In the alkaline,
calcareous soils often found in the Hill Country, it is prone to iron chlorosis (yellowing of leaves) and
can struggle with the heat and drought.
, 9. In terms of plant classification, what type of plant is a dandelion that grows in a lawn?
A. Annual
B. Biennial
C. Perennial
D. Ephemeral
Correct Answer: C. Perennial
Rationale: The common dandelion is a perennial weed. It lives for more than two years and will
regrow from its deep taproot year after year. While it does produce seeds prolifically, its ability to
persist is due to its perennial nature, making it challenging to eradicate.
10. A resident finds a black, sooty mold growing on the leaves of their citrus tree. What is the most
likely underlying cause of this issue?
A. A fungal disease that infects the leaves directly
B. An infestation of sap-sucking insects like aphids or whiteflies that excrete honeydew
C. A nutrient deficiency, specifically a lack of magnesium
D. A viral infection that is systemic within the plant
Correct Answer: B. An infestation of sap-sucking insects like aphids or whiteflies that excrete
honeydew
Rationale: Sooty mold is a black, powdery fungus that grows on the honeydew (a sugary, sticky
substance) secreted by sap-sucking insects such as aphids, whiteflies, and scale. The fungus does not
infect the plant itself but grows on the honeydew, reducing photosynthesis by covering the leaves.
Managing the insect population is the solution.
11. Which part of the plant is responsible for the transport of water and dissolved minerals from
the roots to the leaves?
A. Phloem
B. Xylem
C. Cambium
D. Stomata
Correct Answer: B. Xylem
Rationale: The xylem is the plant's vascular tissue responsible for transporting water and dissolved
minerals upward from the roots. The phloem transports sugars (food) produced in the leaves down or
to other parts of the plant. The cambium is the meristematic tissue that produces new xylem and
phloem (secondary growth), and stomata are pores on the leaf surface for gas exchange.
12. You are teaching a class on pruning. When is the optimal time to prune most oak trees in Texas
to minimize the risk of Oak Wilt infection?
A. Early spring when new growth begins
B. Late winter (December – February)
QUESTIONS AND VERIFIED ANSWERS | 2026–2027 LATEST
UPDATE | GUARANTEED PASS | DETAILED RATIONALES | FULL
STUDY GUIDE | EXAM PREP | PRACTICE TEST |
CERTIFICATION PREPARATION
1. A homeowner in Central Texas notices their St. Augustine lawn is developing irregular yellow
patches despite regular watering. Upon closer inspection, the blades pull away easily from the
runners. What is the most likely cause?
A. Chinch bug infestation
B. Brown patch fungus
C. Iron chlorosis
D. Over-fertilization with nitrogen
Correct Answer: A. Chinch bug infestation
Rationale: Chinch bugs are a common pest of St. Augustine grass in Texas. They feed by piercing the
grass blades and sucking sap, which causes yellowing and death, and the damaged leaf blades will
easily pull away from the runners. Brown patch fungus typically presents as circular, brownish
patches rather than irregular yellowing, and the grass does not pull away easily. Iron chlorosis causes
yellowing but is usually uniform across the lawn and doesn't affect the blade's attachment to the
runner. Over-fertilization with nitrogen would cause excessive growth and could lead to thatch
buildup, not the specific symptom of blades pulling away.
2. What is the most critical component of Integrated Pest Management (IPM) that should be
implemented first in a Texas landscape?
A. Application of broad-spectrum insecticides
B. Monitoring and correct identification of pests
C. Planting only native species
D. Immediate removal of all affected plants
Correct Answer: B. Monitoring and correct identification of pests
Rationale: The first and most crucial step in IPM is identifying the pest correctly and monitoring its
population. Without proper identification, you cannot determine the best management strategy,
which could be cultural, mechanical, biological, or, as a last resort, chemical. Blindly applying
insecticides (Option A) is a common mistake and works against IPM principles. Planting only natives
(Option C) helps with ecosystem health but is not the first step in IPM; it is a preventative strategy.
Removal (Option D) is a last-resort measure, not the first step.
3. A soil test from a new vegetable garden in East Texas shows a pH of 5.2. What is the most
appropriate amendment to apply, and what is the recommended timeframe for best results?
,A. Apply agricultural lime immediately before planting; it takes effect in two to three weeks.
B. Apply sulfur several months before planting.
C. Apply agricultural lime several months before planting to allow it to react with the soil.
D. No amendment is needed; most vegetables prefer acidic soil.
Correct Answer: C. Apply agricultural lime several months before planting to allow it to react with
the soil.
Rationale: A pH of 5.2 is acidic. The ideal pH for most vegetables is between 6.0 and 7.0 . To raise the
pH, agricultural lime (calcium carbonate) is the standard amendment. The key is that lime reacts
slowly with the soil; it can take several months to see a significant change, so it should be applied
well in advance of planting. Sulfur is used to lower pH. While some plants like blueberries love acidic
soil, most vegetables prefer a more neutral range.
4. In the Texas Master Gardener handbook, the term "Earth-Kind" landscaping is a foundational
concept. What is the primary goal of this approach?
A. To create a landscape that requires no supplemental water
B. To use only native Texas plants in the landscape design
C. To promote environmentally responsible landscaping that conserves water and reduces chemical
use
D. To achieve a traditional, high-maintenance lawn with a manicured appearance
Correct Answer: C. To promote environmentally responsible landscaping that conserves water and
reduces chemical use.
Rationale: The Earth-Kind Landscaping system, developed by Texas A&M AgriLife Extension, uses
research-proven techniques to create beautiful, sustainable landscapes. It focuses on reducing water
use, fertilizer, and pesticide application while still allowing for a wide selection of plants that are
adapted to Texas conditions. The goal is not to require no water (Option A) but rather to use it
efficiently. It also encourages using adapted plants, not exclusively natives (Option B). High-
maintenance lawns (Option D) are the antithesis of the Earth-Kind philosophy.
5. A Master Gardener is advising a homeowner on the proper way to water their lawn. Which of
the following is the most water-efficient irrigation method for a new shrub border?
A. Overhead sprinklers that apply water quickly in a 15-minute cycle
B. A soaker hose placed under a layer of mulch
C. A drip irrigation system with emitters at the base of each plant
D. Frequent hand watering to keep the soil surface moist
Correct Answer: C. A drip irrigation system with emitters at the base of each plant
Rationale: Drip irrigation is the most efficient method because it delivers water directly to the plant's
root zone, minimizing evaporation and runoff . A soaker hose (Option B) is also efficient for beds but
can be less precise and more suited for row crops or mass plantings. Overhead sprinklers (Option A)
are prone to high water loss from evaporation and wind drift. Frequent hand watering (Option D) is
often inefficient and can lead to shallow root systems.
,6. A gardener is preparing their vegetable bed and reads on a fertilizer bag "10-20-10." What does
the number "20" represent?
A. The percentage of Nitrogen (N) in the mix
B. The percentage of Phosphorus (P₂O₅) in the mix
C. The percentage of Potassium (K₂O) in the mix
D. The amount of trace minerals in the fertilizer
Correct Answer: B. The percentage of Phosphorus (P₂O₅) in the mix
Rationale: The three numbers on a fertilizer bag represent the N-P-K ratio (Nitrogen, Phosphorus,
Potassium) in that specific order. Therefore, 10-20-10 means the fertilizer contains 10% Nitrogen, 20%
Phosphorus (as P₂O₅), and 10% Potassium (as K₂O) . Phosphorus is crucial for root development and
flowering.
7. You are helping a community garden choose a mulch for their vegetable beds. What is the most
significant benefit of applying a 2- to 3-inch layer of organic mulch like shredded leaves or pine
bark?
A. It significantly raises the soil's pH over time.
B. It adds large amounts of nitrogen to the soil.
C. It conserves soil moisture, suppresses weeds, and moderates soil temperature.
D. It provides a habitat for beneficial insects, which reduces pest populations.
Correct Answer: C. It conserves soil moisture, suppresses weeds, and moderates soil temperature.
Rationale: The primary functional benefits of mulching are water conservation (reducing
evaporation), weed suppression (blocking sunlight to weed seeds), and moderating soil
temperatures. While organic mulches do add some organic matter to the soil as they decompose,
they are not a significant source of nitrogen (Option B) and do not raise the soil pH (Option A). While
they can provide habitat for some beneficial insects, this is a secondary benefit, not the primary
function (Option D).
8. A homeowner in the Hill Country wants to plant a drought-tolerant ornamental tree. Which tree
is not well-suited to Texas conditions and would likely suffer from high water needs and iron
chlorosis?
A. Texas Redbud
B. Cedar Elm
C. Southern Magnolia
D. Live Oak
Correct Answer: C. Southern Magnolia
Rationale: While the Southern Magnolia is a beautiful tree, it is not as drought-tolerant as the Texas
Redbud, Cedar Elm, or Live Oak. It prefers moist, well-drained, slightly acidic soils. In the alkaline,
calcareous soils often found in the Hill Country, it is prone to iron chlorosis (yellowing of leaves) and
can struggle with the heat and drought.
, 9. In terms of plant classification, what type of plant is a dandelion that grows in a lawn?
A. Annual
B. Biennial
C. Perennial
D. Ephemeral
Correct Answer: C. Perennial
Rationale: The common dandelion is a perennial weed. It lives for more than two years and will
regrow from its deep taproot year after year. While it does produce seeds prolifically, its ability to
persist is due to its perennial nature, making it challenging to eradicate.
10. A resident finds a black, sooty mold growing on the leaves of their citrus tree. What is the most
likely underlying cause of this issue?
A. A fungal disease that infects the leaves directly
B. An infestation of sap-sucking insects like aphids or whiteflies that excrete honeydew
C. A nutrient deficiency, specifically a lack of magnesium
D. A viral infection that is systemic within the plant
Correct Answer: B. An infestation of sap-sucking insects like aphids or whiteflies that excrete
honeydew
Rationale: Sooty mold is a black, powdery fungus that grows on the honeydew (a sugary, sticky
substance) secreted by sap-sucking insects such as aphids, whiteflies, and scale. The fungus does not
infect the plant itself but grows on the honeydew, reducing photosynthesis by covering the leaves.
Managing the insect population is the solution.
11. Which part of the plant is responsible for the transport of water and dissolved minerals from
the roots to the leaves?
A. Phloem
B. Xylem
C. Cambium
D. Stomata
Correct Answer: B. Xylem
Rationale: The xylem is the plant's vascular tissue responsible for transporting water and dissolved
minerals upward from the roots. The phloem transports sugars (food) produced in the leaves down or
to other parts of the plant. The cambium is the meristematic tissue that produces new xylem and
phloem (secondary growth), and stomata are pores on the leaf surface for gas exchange.
12. You are teaching a class on pruning. When is the optimal time to prune most oak trees in Texas
to minimize the risk of Oak Wilt infection?
A. Early spring when new growth begins
B. Late winter (December – February)
