Course outline
Module 1
Module 1: Soil Health and Composting
Soil Health and Composting
Knowledge check
Q1. What is the primary benefit of adding organic matter such as compost to garden soil?
- A. It immediately raises soil pH to neutral
- B. It improves soil structure, water retention, and nutrient availability ✓
- C. It kills soil pests and pathogens completely
- D. It replaces the need for any watering
Why: Organic matter binds soil particles into crumbly aggregates, helps soil hold water and nutrients, and feeds beneficial soil organisms. It does not instantly change pH, eliminate all pests, or remove the need for watering.
Q2. Which of the following is the best description of the ideal ratio of carbon-rich to nitrogen-rich materials in a compost pile?
- A. Roughly 1 part carbon to 1 part nitrogen
- B. Roughly 30 parts carbon to 1 part nitrogen ✓
- C. Roughly 1 part carbon to 30 parts nitrogen
- D. Carbon and nitrogen should never be combined
Why: A carbon-to-nitrogen ratio near 30:1 is generally recommended for efficient decomposition. Too much nitrogen leads to odor and slimy material, while too much carbon slows decomposition considerably.
Q3. Which material is classified as a 'green' (nitrogen-rich) compost ingredient?
- A. Dry autumn leaves
- B. Wood chips
- C. Fresh grass clippings ✓
- D. Shredded cardboard
Why: Fresh grass clippings, along with fruit and vegetable scraps and manure, are nitrogen-rich 'greens.' Dry leaves, wood chips, and cardboard are carbon-rich 'browns.'
Q4. What is the main purpose of turning or aerating a compost pile?
- A. To add more water to the pile
- B. To introduce oxygen that supports aerobic decomposition ✓
- C. To cool the pile down to room temperature
- D. To separate the nitrogen from the carbon permanently
Why: Aerobic microorganisms that break down compost need oxygen. Turning the pile supplies air, speeds decomposition, and helps prevent foul odors that come from anaerobic conditions.
Q5. What does the soil term 'humus' refer to?
- A. Loose sand particles that drain water quickly
- B. Stable, dark, decomposed organic matter that improves soil fertility ✓
- C. Fresh plant residue that has not yet begun to decay
- D. A synthetic fertilizer pellet
Why: Humus is the stable end product of organic matter decomposition. It is dark in color, holds nutrients and moisture well, and contributes greatly to soil fertility and structure.
Module 2
Module 2: Companion Planting Strategies
Companion Planting Strategies
Knowledge check
Q1. What is the main purpose of companion planting in an organic garden?
- A. To increase the use of synthetic fertilizers
- B. To grow plants that benefit each other through pest control, pollination, or soil improvement ✓
- C. To plant as many different species as possible in a single bed regardless of their needs
- D. To replace crop rotation entirely
Why: Companion planting pairs plants that support one another, for example by repelling pests, attracting pollinators, or improving soil, which reduces the need for synthetic inputs.
Q2. Which plant is commonly grown alongside tomatoes because it is said to repel tomato hornworms and whiteflies?
- A. Basil ✓
- B. Fennel
- C. Potatoes
- D. Cabbage
Why: Basil is a classic companion for tomatoes; gardeners value it for deterring pests such as hornworms and whiteflies, and many believe it also improves the flavor of tomatoes nearby.
Q3. Why are legumes such as beans and peas often recommended as companions for heavy feeders like corn and squash?
- A. Legumes repel all insects from the garden
- B. Legumes fix atmospheric nitrogen into the soil through root bacteria, benefiting nitrogen-hungry neighbors ✓
- C. Legumes shade the soil so weeds cannot grow
- D. Legumes release chemicals that stunt the growth of nearby plants
Why: Legumes host nitrogen-fixing bacteria in their root nodules, which enriches the soil with nitrogen that heavy feeders like corn and squash need.
Q4. Which pairing is generally considered a poor companion combination to avoid?
- A. Carrots and onions
- B. Beans and garlic
- C. Fennel and most other vegetables ✓
- D. Marigolds and tomatoes
Why: Fennel releases compounds that inhibit the growth of many vegetables, so it is usually planted in its own area rather than alongside them.
Q5. What is a common benefit of planting flowers such as calendula or alyssum among vegetable crops?
- A. They attract beneficial insects like hoverflies and ladybugs that prey on garden pests ✓
- B. They increase soil acidity to prevent disease
- C. They eliminate the need for watering
- D. They produce nitrogen directly in the leaves
Why: Flowering plants provide nectar and pollen that attract predatory and pollinating insects, which help control pest populations naturally without chemical sprays.
Module 3
Module 3: Natural Pest Management
Natural Pest Management
Knowledge check
Q1. Which of the following is a key principle of organic natural pest management?
- A. Applying broad-spectrum synthetic insecticides at the first sign of pests
- B. Encouraging beneficial insects and maintaining a balanced garden ecosystem ✓
- C. Removing all insects from the garden so no pests can return
- D. Using chemical fertilizers to make plants strong enough to resist pests
Why: Organic pest management emphasizes working with nature by supporting beneficial insects such as ladybugs and lacewings, which help keep pest populations in check over time.
Q2. What does the term 'companion planting' refer to in natural pest management?
- A. Growing only one crop variety across a large area to simplify care
- B. Planting different species together so they help deter pests or attract beneficial insects ✓
- C. Keeping pets in the garden to eat insects
- D. Watering plants at the same time each day to reduce stress
Why: Companion planting pairs plants that support each other, for example marigolds near tomatoes may deter certain nematodes, while flowering herbs can attract predatory insects.
Q3. Which of these is an example of a physical or mechanical pest control method?
- A. Releasing parasitic wasps into the garden
- B. Spraying neem oil on affected leaves
- C. Hand-picking caterpillars from plants and placing row covers over crops ✓
- D. Applying pyrethrin dust to the soil surface
Why: Hand-picking pests and using physical barriers like row covers are mechanical methods that prevent or remove pests without relying on biological agents or botanical sprays.
Q4. Why is crop rotation useful for managing pests in an organic garden?
- A. It adds nitrogen to the soil from the plants' roots
- B. It disrupts the life cycles of pests that specialize on particular plant families ✓
- C. It makes all vegetables ripen at the same time for easier harvest
- D. It increases the number of weeds, which trap pests away from crops
Why: Many pests target specific plant families, so moving crops to a new location each season breaks the pest's food supply and reduces population buildup in the soil.
Q5. Which botanical or biological spray is commonly used as a natural insecticide in organic gardening?
- A. Sodium chloride (table salt) solution applied directly to roots
- B. Neem oil, derived from the seeds of the neem tree ✓
- C. Kerosene mixed with water
- D. Ammonia-based household cleaner
Why: Neem oil is a plant-derived product that disrupts insect feeding and growth and is approved for use in organic systems, making it a widely recommended natural pest control option.
Module 4
Module 4: Water Conservation Techniques
Water Conservation Techniques
Knowledge check
Q1. Which watering method delivers water directly to the soil at the plant's roots while minimizing evaporation and runoff?
- A. Overhead sprinkling
- B. Drip irrigation ✓
- C. Flood irrigation
- D. Hand-spraying the foliage
Why: Drip irrigation releases water slowly at the base of plants, so it reaches the root zone with little evaporation or runoff, making it one of the most water-efficient methods for gardens.
Q2. What is the main benefit of applying a layer of organic mulch around garden plants?
- A. It increases the soil's pH to neutral
- B. It reduces soil moisture loss through evaporation ✓
- C. It encourages rapid weed germination
- D. It makes the soil drain more quickly
Why: Mulch shades the soil surface and creates a barrier that slows evaporation, helping the soil retain moisture for longer periods between waterings.
Q3. What is the best time of day to water an organic garden to minimize water loss?
- A. Midday when the sun is strongest
- B. Late evening after sunset
- C. Early morning before 10 a.m. ✓
- D. Mid-afternoon during peak heat
Why: Watering early in the morning allows water to soak in before the heat of the day increases evaporation, and it gives foliage time to dry, which helps prevent fungal diseases.
Q4. Which practice helps improve soil's ability to hold water over time?
- A. Tilling the soil deeply and frequently
- B. Adding compost to increase organic matter ✓
- C. Removing all plant residue from the bed
- D. Compacting the soil to create a firm surface
Why: Compost improves soil structure and increases organic matter, which acts like a sponge that absorbs and holds water, reducing how often you need to irrigate.
Q5. What is rainwater harvesting in a garden context?
- A. Letting rain flow off roofs into storm drains
- B. Collecting and storing rainwater from roofs or surfaces for later garden use ✓
- C. Planting only in areas where rain never falls
- D. Covering the entire garden with plastic during storms
Why: Rainwater harvesting captures precipitation, often using barrels or cisterns attached to downspouts, providing a free, chemical-free water source for irrigating plants during dry periods.
Module 5
Module 5: Crop Rotation and Planning
Crop Rotation and Planning
Knowledge check
Q1. What is the main purpose of crop rotation in organic gardening?
- A. To increase the amount of water needed by plants
- B. To reduce soil-borne pests and diseases and maintain soil fertility ✓
- C. To grow the same crop in the same spot for maximum yield
- D. To eliminate the need for compost entirely
Why: Rotating crops prevents pests and pathogens that target specific plant families from building up in the soil, and varying crop types helps balance nutrient demands.
Q2. Which plant families are considered heavy feeders that deplete soil nitrogen?
- A. Legumes such as beans and peas
- B. Brassicas such as cabbage and broccoli ✓
- C. Alliums such as onions and garlic
- D. Herbs such as parsley and dill
Why: Brassicas are heavy nitrogen feeders, so they are typically planted after legumes, which fix nitrogen into the soil, rather than being followed by other heavy feeders.
Q3. Why are legumes often planted in a rotation cycle?
- A. They repel all garden insects
- B. They add nitrogen to the soil through root bacteria ✓
- C. They require very little sunlight to grow
- D. They prevent weeds from germinating
Why: Legumes host nitrogen-fixing bacteria in their root nodules, which enriches the soil with nitrogen for the crops that follow.
Q4. A common four-year rotation groups crops into which sequence?
- A. Legumes, leafy greens, fruiting crops, root crops ✓
- B. Root crops, legumes, fruiting crops, leafy greens
- C. Fruiting crops, fruiting crops, leafy greens, legumes
- D. Leafy greens, root crops, legumes, fruiting crops
Why: A typical organic rotation starts with legumes to restore nitrogen, followed by leafy greens, then fruiting crops, and finally root crops, which benefit from the loosened, enriched soil.
Q5. What is a good practice when planning a garden layout for future rotation?
- A. Record what was planted in each bed each season ✓
- B. Plant the same crop in the same bed every year
- C. Avoid writing anything down so you stay flexible
- D. Move all crops to a new location every single week
Why: Keeping a written or mapped record of each bed's planting history makes it easy to plan rotations and avoid planting related crops in the same spot too soon.
Module 6
Module 6: Organic Seed Saving
Organic Seed Saving
Knowledge check
Q1. Why is it important to save seeds from open-pollinated plants rather than hybrid plants in an organic garden?
- A. Open-pollinated plants always produce larger harvests than hybrids
- B. Open-pollinated plants produce seeds that grow true to type, so the next generation resembles the parent plant ✓
- C. Hybrid seeds are illegal to save in most countries
- D. Hybrid plants cannot be grown organically
Why: Open-pollinated varieties are stable and breed true, meaning seeds saved from them will produce plants with similar characteristics. Seeds saved from hybrids often segregate, producing offspring that vary widely and may not resemble the parent.
Q2. Which of the following is the most common method for drying seeds after harvest?
- A. Storing them in a sealed plastic bag while still moist
- B. Spreading them on a paper towel or screen in a warm, dry, well-ventilated area ✓
- C. Placing them in direct sunlight on a hot pavement for several hours
- D. Soaking them in water for 24 hours
Why: Seeds should be dried thoroughly in a cool or warm dry area with good airflow to prevent mold and rot. Direct intense heat can damage the embryo, and sealing moist seeds encourages fungal growth.
Q3. What does it mean for a seed to be 'viable'?
- A. The seed has a bright color and smooth coat
- B. The seed is large enough to be sold commercially
- C. The seed is alive and capable of germinating and growing into a plant ✓
- D. The seed has been treated with organic fungicide
Why: Seed viability refers to the living embryo's ability to sprout under suitable conditions. Viability declines over time and is affected by storage conditions, which is why germination tests are useful before planting saved seed.
Q4. Why do gardeners isolate certain plants when saving seed from crops like squash or corn?
- A. To make the plants grow taller
- B. To prevent cross-pollination with other varieties of the same species, which would change the seed's characteristics ✓
- C. To increase the amount of sunlight the plants receive
- D. To protect the plants from insects only
Why: Many crops cross-pollinate readily through wind or insects. Isolation by distance, time, or physical barriers such as bagging flowers helps keep the seed true to its variety.
Q5. Which storage condition best preserves saved seeds over several years?
- A. A warm, humid kitchen cabinet near the stove
- B. A cool, dark, dry, airtight container, such as a glass jar with a desiccant ✓
- C. An open cardboard box in a sunny window
- D. A damp basement shelf wrapped in newspaper
Why: Seeds stay viable longest when kept cool, dry, and dark, with low humidity. Airtight containers with desiccants like silica gel protect against moisture, which is the main factor that shortens seed life.
Module 7
Module 7: Mulching and Weed Control
Mulching and Weed Control
Knowledge check
Q1. What is the primary purpose of applying mulch in an organic garden?
- A. To increase soil acidity for acid-loving plants
- B. To conserve soil moisture and suppress weed growth ✓
- C. To attract earthworms that consume pest insects
- D. To provide a chemical fertilizer boost to plant roots
Why: Mulch covers the soil surface, reducing evaporation so moisture is retained, and it blocks light that weed seeds need to germinate, making it a core tool for weed control without synthetic herbicides.
Q2. Which of the following is an example of an organic mulch material?
- A. Black plastic sheeting
- B. Crushed rock
- C. Wood chips ✓
- D. Landscape fabric made from polypropylene
Why: Wood chips are an organic material that breaks down over time, adding organic matter to the soil. Plastic sheeting, crushed rock, and synthetic landscape fabric are inorganic and do not contribute to soil health.
Q3. Why should mulch be kept a few inches away from the base of plant stems and tree trunks?
- A. Mulch placed against stems blocks sunlight needed for photosynthesis
- B. Mulch touching stems can trap moisture and encourage rot and pest problems ✓
- C. Mulch against stems causes the plant to produce more flowers than leaves
- D. Mulch near stems raises the soil pH to dangerous levels
Why: Mulch piled directly against stems or trunks holds excess moisture against the bark, which can cause rot, fungal disease, and attract rodents or insects that damage the plant.
Q4. What is a beginner-friendly method of weed control that combines well with mulching?
- A. Spraying broad-spectrum synthetic herbicide before mulching
- B. Hand-pulling weeds when the soil is moist and before they set seed ✓
- C. Tilling the soil deeply every week during the growing season
- D. Watering weeds heavily so their roots rot
Why: Hand-pulling is an effective organic method, especially when soil is moist so roots come out whole. Removing weeds before they set seed reduces future weed pressure, and a mulch layer then helps prevent new ones.
Q5. Approximately how thick should a layer of organic mulch generally be applied for good weed suppression?
- A. Half an inch, applied as a thin dusting
- B. Two to three inches ✓
- C. Eight to ten inches for every bed
- D. One foot deep across the whole garden
Why: A layer of about two to three inches is usually sufficient to block most weed seed light and reduce evaporation. Thinner layers may let weeds through, while excessively deep mulch can limit air and water reaching the soil.