Project Grade 4 Health & Consumer Science
Garden to Salad Bar at Harlowick Elementary: A Produce Safety Plan
A four-session grade 4 health project in which teams run a soil-splash test, choose how to water a school garden, and write a produce rinse plan for the cafeteria.
Objectives
- Students will describe four ways germs can reach garden vegetables and explain how water can carry them.
- Students will run a soil-splash test and use their counts to choose a watering method for each garden bed.
- Students will write a step card for rinsing produce that a younger student can follow without help.
Vocabulary
Key words: germ, produce, splash, soaker hose, rinse, untreated water
Teacher overview
Farms that grow lettuce and other leafy greens pay close attention to which water touches the part of the plant people eat, because water, soil, and hands can all carry germs onto food that is served raw. In this four-session project, fourth graders at the fictional Harlowick Elementary prepare a produce safety plan so the school garden's lettuce, cherry tomatoes, and carrots can go on the cafeteria salad bar. Teams trace the ways germs reach a salad, run a soil-splash test, choose a watering tool and water source for each bed, and write a rinse station step card. The final deliverables are a garden shed poster, a step card, and a three-minute talk to the fictional cafeteria manager and school nurse, roles the teacher or two other adults can play.
Two misconceptions tend to surface in the first session. Many students believe that washing vegetables with soap makes them cleaner, yet food-safety guidance advises plain running water, because soap can soak into produce and leave a residue that upsets the stomach. Many also assume rain barrel water is clean because it falls from the sky, while water collected from a roof carries whatever was on the roof, including bird droppings. The nurse's rules in the brief build in both points, so the rubric can check that each team's plan reflects them.
Project Brief
Driving question: How can our class keep the garden's lettuce, tomatoes, and carrots safe to eat on the salad bar?
The situation. Harlowick Elementary is a school in the fictional town of Harlowick. Its garden has four beds: lettuce, cherry tomatoes, carrots, and flowers. Ms. Adeyemi runs the cafeteria. She will put garden food on the salad bar this spring. First, the fourth grade must give her a safety plan she can approve. Nurse Castellano will check that the plan follows her rules.
Fact cards. Read these with your team.
- Germs that make people sick can get onto food in four main ways. They can come from soil, from animal droppings, from dirty hands, and from dirty water.
- When water hits bare soil hard, it can splash soil up onto leaves. People eat lettuce leaves raw, so soil on them matters.
- Harlowick tap water is treated to make it safe to drink.
- The rain barrel water is not treated. Birds sit on the shed roof, and rain washes their droppings into the barrel.
- Wash your hands with soap and water before you pick food. Wash them again before you rinse it.
- Rinse food under cool running tap water just before it is eaten. Rub leaves gently with your hands. Scrub firm food, like carrots, with a clean brush.
- Do not use soap on food. Soap can soak in and upset your stomach.
- Dry the food with a clean paper towel.
Nurse Castellano's rules. These are the goals your plan must meet.
- Only tap water may touch the parts of plants that we eat. The rain barrel is for the flower bed.
- The watering plan must keep soil off the lettuce leaves as much as possible.
- Everyone washes hands before picking and before rinsing.
- No soap on food.
Limits. These are the things your plan has to work with.
- The garden has three watering tools. There is a watering can with a sprinkler head, a hose with a spray nozzle, and a soaker hose. A soaker hose lies on the soil and lets water drip out slowly.
- There is only one soaker hose, and it reaches only one bed.
- The rinse station is the classroom sink.
- The step card must fit on a half sheet and have no more than six steps.
- Second graders use the garden too. A second grader must be able to follow your step card without help.
What you turn in.
- A garden shed poster. It shows the ways germs can reach a salad and your watering plan for each bed.
- A rinse station step card.
- A three-minute talk for Ms. Adeyemi and Nurse Castellano.
Milestones
Session 1, trace the germ paths. Read the fact cards with your team. Draw a map of the garden. Show the four beds, the rain barrel, and the tap. Then draw an arrow for each of the four ways germs could reach a salad. Label each arrow. Turn in your labeled map.
Session 2, run the splash test. Your test asks which watering tool splashes the most soil onto leaves. First, write a hypothesis: "We think the ___ will splash the most soil because ___." Next, stand a white card at the edge of the soil tray. The card is your leaf. Draw a square on it that is 5 cm on each side. Pour 200 mL of water onto the soil three ways. Use the watering can held high. Use the spray bottle, which stands in for the hose. Then pour slowly from a cup right at the soil, which stands in for the soaker hose. The spray bottle takes many squeezes to empty, so team members can take turns. Use a new card and smooth the soil each time. Count the soil specks inside the square. Keep the water amount, the card, and its place the same every time. Only the tool changes. Wash your hands with soap and water after you touch the soil. Turn in your hypothesis and this table.
| Watering tool | Soil specks inside the square |
|---|---|
| Watering can, held high | |
| Spray bottle (hose) | |
| Cup poured at the soil (soaker hose) |
Session 3, compare and choose. Make a table that checks each watering tool against the nurse's rules and the limits. Use your splash counts as evidence. Remember that there is only one soaker hose. Decide which tool will water each bed and which water it will use. Then draft your poster and your step card. Turn in the table and both drafts.
Session 4, test, fix, and present. Trade step cards with another team. One person from that team follows your card at the sink with a carrot and a lettuce leaf. Your team watches without talking and notes any step that confuses the tester. Fix those steps. Then give your three-minute talk. Turn in your final poster and step card.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
| Criterion | 1 Emerging | 2 Developing | 3 Proficient | 4 Advanced |
|---|---|---|---|---|
| Germ paths and health facts | The map shows fewer than two germ paths, or the poster states a fact that is wrong, such as using soap on food. | The map shows two or three germ paths, and the poster repeats facts without linking them to the garden. | The map shows all four germ paths with labels, and the poster explains how each one is blocked in this garden. | All four paths are labeled and blocked, and the team explains why raw lettuce needs more care than a carrot that will be scrubbed. |
| Splash test and watering plan | No test data appears, or the plan puts rain barrel water on a food bed. | The test was run, but the watering plan does not use the counts or ignores the one-soaker-hose limit. | The plan uses the splash counts to assign a tool to each bed, keeps rain barrel water on flowers only, and gives the one soaker hose to a single bed. | The plan meets every rule and limit, and the team explains which bed gets the soaker hose by comparing counts and the way each plant grows. |
| Rinse station step card | The card is missing handwashing or running water, or it includes soap on food. | The card has the key steps, but it has more than six steps or the tester could not follow it. | The card has six steps or fewer in order: wash hands, rinse under running water, rub or scrub, and dry with a clean towel; the tester followed it. | The card meets every requirement, and the team shows one change it made after watching the tester. |
| Talk and teamwork | The talk leaves out the watering plan or the step card. | The talk covers the plan, but it runs well past three minutes or only one member speaks. | The talk covers the map, plan, and card in about three minutes, and every member speaks. | The talk is clear and timed, and the team answers a question from the adults using its splash data. |
Differentiation
Support
Give these teams a pre-drawn garden map with the four beds, the rain barrel, and the tap already in place, so Session 1 centers on the germ-path arrows. Provide a step card frame with six numbered boxes and small picture icons (a soap bar, a faucet, a brush, a paper towel) that students arrange in order before writing each step. Read the fact cards aloud and let teams highlight one key word per card.
Extension
Ask teams to run a second splash test that changes only the height of the watering can, pouring once from high and once from just above the soil, and to write two sentences about whether a careful gardener could use the watering can on the lettuce bed if the soaker hose were needed elsewhere. Teams can also add a note to the poster explaining why tomatoes growing on stakes face less splash than lettuce growing at soil level.
ELL supports
Pre-teach "soil," "splash," "rinse," "scrub," "soaker hose," and "rain barrel" with photographs or real objects before Session 1, and label each object on the materials table. Provide sentence frames for the talk: "We chose the ___ for the lettuce bed because our test showed ___." and "The first step on our card is ___ because ___." Allow step cards to use a picture beside each short sentence.
Extensions
Invite the school nurse or the cafeteria manager to hear the final talks in person and to ask one question of each team. Students can also take home a copy of the step card and write a short note about one change their family could make when rinsing fruits and vegetables at home.