Fall Garden Investigators: Planning, Planting, and Saving Heirloom Crops

Big-Picture Goals

Over four weeks, the learner will design and begin a fall garden suited to the learner’s location in Yavapai County, Arizona. Because Yavapai County includes several elevations and climates, the learner will use local frost dates, sunlight, soil conditions, and University of Arizona Cooperative Extension information to make gardening decisions.

• Explain what heirloom seeds and bulbs are and why gardeners save them.
• Plan a fall garden with carrots, garlic, onions, snap peas, and other appropriate plants.
• Test and improve garden soil using hydrated coco coir and other suitable organic matter.
• Plant heirloom seeds and bulbs correctly and label them for future care.
• Explain how to save seeds and bulbs for replanting in later years.
• Prepare snap pea seeds and young plants for winter using mulch, moisture checks, and protection from extreme cold.
• Read and use gardening information from University of Arizona Cooperative Extension and Yavapai County gardening resources.
• Keep a garden journal with observations, measurements, drawings, questions, and decisions.

Materials for the Unit

• Garden journal, pencils, colored pencils, ruler, measuring tape, and clipboard
• Graph paper or digital garden-planning tool
• Access to University of Arizona Cooperative Extension and Arizona Yavapai Gardens articles
• Local frost-date information and a simple thermometer
• Garden bed, containers, or a selected planting area
• Garden soil, finished compost, and coco coir
• Watering can or hose with a gentle spray
• Hand trowel, small rake, gloves, and labels
• Heirloom carrot seeds, garlic bulbs or cloves, onion seeds or sets, and snap pea seeds
• Optional additional fall seeds suited to the learner’s local elevation
• Mulch such as clean straw, shredded leaves, or untreated plant material
• Small containers for seed testing and collecting soil samples
• String or sticks for marking rows
• Camera or tablet for recording garden progress

Success Criteria

By the end of the unit, the learner will be successful when they can:

• Define heirloom seed, open-pollinated, bulb, compost, coco coir, and mulch in their own words.
• Create a labeled garden plan that shows crops, spacing, sunlight, planting dates, and winter protection.
• Explain that coco coir helps hold water and improve soil texture but does not provide all the nutrients plants need.
• Plant carrots, garlic, onions, and snap peas using careful labels and appropriate depth and spacing.
• Describe at least two ways to care for a garden during winter.
• Use evidence from at least two gardening articles to explain one planting or care decision.
• Make a clear presentation, garden map, or journal portfolio showing what was learned.

Week 1: Explore Local Fall Gardening and Heirloom Plants

Weekly focus: Learn what grows in the local area, understand heirloom seeds and bulbs, and begin a garden plan.

Day 1: Garden Mystery Hook and Local Conditions

Ask: “If you planted the same seed in a high mountain garden and a lower desert garden, would it grow the same way?” Discuss sunlight, elevation, temperature, water, and frost. Look up the learner’s approximate elevation and local first-frost information, then record these details in the garden journal.

Day 2: What Makes a Seed Heirloom?

Explain that an heirloom seed comes from a plant variety that has been grown and passed down for many years, often by families or communities. Explain that many heirloom varieties are open-pollinated, meaning they can produce seeds that grow plants similar to the parent when pollination is managed carefully. Have the learner compare seed packets and write three observations about names, colors, shapes, or growing days.

Day 3: Seeds, Bulbs, and Future Gardens

Show a carrot seed, pea seed, onion seed or set, and garlic bulb or clove. Explain that a bulb is a short underground plant structure that stores food and can grow into a new plant; garlic cloves and many onion sets are examples. The learner draws and labels each starting structure and explains how a gardener might save it for the next year.

Day 4: Read Like a Garden Scientist

Read one age-appropriate article from Arizona Yavapai Gardens or the University of Arizona Cooperative Extension about fall planting, local conditions, soil, or a selected crop. Use a “notice, wonder, use” chart: record one important fact, one question, and one idea that could help the garden.

Day 5: Draft the Garden Map

Measure the available garden space or choose container sizes. The learner drafts a map showing north, sunlight, paths, crops, labels, and approximate spacing, then chooses one crop to grow in a container if space is limited.

Week 1 Check for Understanding

The learner explains the difference between an heirloom seed and a bulb, identifies two local growing conditions that affect planting, and points to where carrots, garlic, onions, and snap peas will go on the garden map.

Week 2: Prepare and Refresh the Soil

Weekly focus: Investigate soil, hydrate and use coco coir correctly, and improve the planting area without treating coco coir as fertilizer.

Day 1: Soil Investigation

Collect a small soil sample from the planting area and examine its color, texture, smell, and ability to hold together when slightly damp. Test drainage by pouring a small amount of water onto the soil and observing whether it soaks in, runs off, or stays in a puddle. Record the results in the journal.

Day 2: Understanding Coco Coir

Explain that coco coir is made from coconut fiber and can help soil hold moisture while making it lighter and easier for roots to grow through. Emphasize that coco coir is not a complete plant food, so finished compost or another appropriate soil amendment may also be needed. The learner predicts what will happen when dry coco coir is placed in water.

Day 3: Hydrate and Mix Safely

Following the package directions, place coco coir in a container and add water slowly while observing how it expands. Mix the hydrated coir with garden soil and finished compost according to local gardening guidance and available soil needs; avoid making the mixture mostly coir. The learner describes how the mixture feels before and after it is prepared.

Day 4: Build the Planting Area

Remove large weeds and rocks without disturbing the soil more than necessary. Loosen the top layer, add the prepared soil mixture, and smooth the planting surface. Discuss why healthy soil includes air spaces, water, nutrients, living organisms, and room for roots.

Day 5: Soil and Compost Observation

Compare a small sample of original soil with the refreshed mixture using sight and touch. The learner makes a simple “before and after” page with labels and writes one caution about using too much water or too much coco coir. Water the bed gently if it is dry.

Week 2 Check for Understanding

The learner explains what coco coir does, what it does not do, and why compost or another nutrient source may be useful. The learner also identifies one sign of poor drainage and one sign that soil has enough moisture for planting.

Week 3: Plant Heirloom Carrots, Garlic, Onions, and Snap Peas

Weekly focus: Use the garden plan to plant carefully, record evidence, and make adjustments based on local conditions and seed-package directions.

Day 1: Planting Rules and Seed Math

Read the planting directions on each seed packet or bulb label, paying attention to depth, spacing, sunlight, days to harvest, and local frost information. Practice measuring planting depth with a ruler and calculate how many plants can fit in one row. The learner updates the garden map with exact spacing.

Day 2: Plant Heirloom Carrots

Make shallow, straight rows for carrot seeds because carrot seeds are small and should not be buried deeply. Place seeds with as much even spacing as possible, cover lightly, label the row, and water gently so the seeds do not wash away. Discuss why carrots may need careful thinning after they sprout.

Day 3: Plant Garlic and Onions

Separate a healthy garlic bulb into cloves and plant each clove with the pointed end facing upward, using the depth and spacing recommended for the local area. Plant onion seeds or sets according to their directions, then label the varieties clearly. Explain that garlic and onions store food in underground structures and need time to develop roots before winter.

Day 4: Plant Snap Peas

Plant snap peas at the recommended depth and spacing, and provide a small trellis or support if appropriate. Talk about how peas prefer cool weather and how local elevation changes the best planting time. The learner records the date, weather, soil condition, and number of seeds planted.

Day 5: Garden Label and Observation Day

Check every row or container for clear labels, correct moisture, and safe spacing. The learner sketches the garden from above and takes a measurement or photograph to use as a baseline. Discuss what may happen if the weather becomes unusually hot, dry, wet, or cold.

Week 3 Check for Understanding

The learner demonstrates how to plant a seed and a garlic clove at different depths, explains why labels matter, and uses the garden map to locate each crop. The learner also states one change that could be made if the soil is too dry or too wet.

Week 4: Winterize Snap Peas and Plan for Future Years

Weekly focus: Protect the garden from winter conditions, understand seed and bulb saving, and present evidence of learning.

Day 1: What Does Winterizing Mean?

Explain that winterizing means preparing plants and soil for cold, wind, dry air, and sudden temperature changes. Read a University of Arizona Cooperative Extension or Arizona Yavapai Gardens article about cool-season crops, frost, mulch, or local winter care. The learner highlights one recommendation that applies to snap peas and one that may not apply because of local elevation.

Day 2: Protect Snap Peas in the Ground

Check whether snap pea seeds or seedlings are too wet, too dry, or exposed to strong wind. Once the soil is not waterlogged, add a loose layer of clean mulch around—but not tightly against—the plants or planting rows. Discuss that mulch can reduce temperature swings and moisture loss, while excessive mulch or standing water can cause problems.

Day 3: Prepare for Frost and Weather Changes

Use the local forecast and frost information to make a simple decision chart: leave plants uncovered, add temporary protection, or check them after a cold night. Discuss safe temporary coverings and why plastic should not rest directly on plant leaves. The learner records the evening temperature, morning temperature, and any visible plant changes.

Day 4: Saving Heirloom Seeds and Bulbs

Explain that seeds are usually saved from mature, healthy plants after the seed has fully developed and dried, while garlic bulbs are saved by choosing healthy bulbs and replanting individual cloves. Onion seed saving can take a longer growing season and careful drying, so the learner identifies which crops may be saved this year and which may need more time. Create labeled envelopes or a storage plan, but do not collect immature or damp seeds.

Day 5: Garden Scientist Presentation

The learner organizes the garden map, journal pages, article notes, soil observations, planting records, and winter-care plan. They present the garden to a family member, teacher, or small group and explain one decision supported by evidence from a University of Arizona or Arizona Yavapai Gardens article.

Week 4 Check for Understanding

The learner explains why snap peas may need mulch or temporary frost protection, describes one risk of overwatering, and gives a basic plan for saving garlic cloves or mature heirloom seeds for a future garden.

End-of-Unit Project: My Local Heirloom Fall Garden Portfolio

The learner creates a portfolio, poster, slide presentation, or short garden tour called My Local Heirloom Fall Garden. The project should include the following:

1. A labeled garden map showing sunlight, crops, spacing, paths or containers, and winter protection.
2. A short explanation of heirloom seeds, open-pollinated plants, bulbs, and seed or bulb saving.
3. A before-and-after soil investigation describing how hydrated coco coir and compost changed the soil texture or moisture-holding ability.
4. A planting record for carrots, garlic, onions, and snap peas, including dates, depths, spacing, and observations.
5. A snap pea winterization plan based on local frost, elevation, weather, and at least one reading from a University of Arizona or Arizona Yavapai Gardens source.
6. A future-garden plan explaining which seeds or bulbs could be saved and how they should be labeled and stored.
7. At least three drawings, measurements, photographs, or data tables showing garden evidence.

Assessment Rubric

• Garden science knowledge: Correctly explains heirloom seeds, bulbs, coco coir, compost, mulch, and winterizing.
• Planning and application: Creates a realistic garden plan that uses local conditions and clear measurements.
• Gardening skills: Demonstrates careful soil preparation, planting, labeling, watering, and winter protection.
• Use of evidence: Refers to observations and at least two reliable gardening readings to support decisions.
• Communication: Presents ideas clearly using accurate vocabulary, organized notes, and useful drawings or data.
• Reflection: Names one success, one challenge, and one change to make in the next growing season.

Differentiation and Flexible Options

• For extra support: Use picture labels, pre-measured rows, sentence starters, read articles aloud, and complete one crop at a time with adult modeling.
• For a small space: Grow carrots, onions, and snap peas in containers; grow garlic in a deep pot with good drainage.
• For advanced learners: Compare two heirloom varieties, graph daily temperatures, calculate germination percentages, or investigate how elevation changes planting dates.
• For digital learning: Use a digital garden map, photograph each stage, and record observations with voice notes.
• For hands-on learning: Measure soil, hydrate coco coir, build a simple trellis, make plant labels, and conduct daily moisture checks.
• For different Yavapai County locations: Follow the learner’s own elevation, frost dates, water availability, and University of Arizona Cooperative Extension recommendations rather than using one planting date for the entire county.