Plant Parts & Needs: A Seed-Growing Experiment at Home

This experiment pairs with the Plant Parts & Needs lesson. Your child will grow seeds and observe every plant part as it appears — roots first, then stems, then leaves — and test what plants need to survive.

What you need

• 8 dried lima beans or pinto beans (from the grocery store)
• 4 zip-lock bags
• Paper towels
• Water
• Tape (to stick bags to a window)
• A notebook and pencil for daily observations
• A ruler for measuring
• Optional: a small pot of soil for transplanting later

The experiment

Part 1: Bag garden setup

Fold a damp paper towel and place it inside a zip-lock bag. Place 2 beans on the paper towel. Seal the bag most of the way (leave a small opening for air). Tape it to a sunny window. Make four bags total.

Part 2: Test what plants need

Set up four conditions:

1. Everything — Sunny window, damp towel (the control)
2. No light — Damp towel, but put the bag in a dark closet
3. No water — Sunny window, but use a dry paper towel
4. Cold — Damp towel, but put the bag in the refrigerator

Part 3: Daily observations

Every day for 10 days, have your child check each bag and record:

• Did anything change?
• Can you see a root? A stem? A leaf?
• How long is the root today? The stem?
• Draw a picture of what the seed looks like each day.

Part 4: Identify the parts

Once the control bag has a visible seedling (usually 4–7 days), have your child identify:

• Roots — The white parts growing downward. What is their job? (They drink water.)
• Stem — The green part growing upward. What is its job? (It delivers water and holds the plant up.)
• Leaves — The small green parts at the top. What is their job? (They make food from sunlight.)
• Seed coat — The shell that falls off. What was its job? (It protected the baby plant.)

Part 5: Compare results

After 10 days, compare all four bags:

• Which seeds grew best? Which did not grow at all?
• What does this tell you about what plants need?

Discussion questions

1. Which plant part appeared first? Why do you think roots come before leaves?
2. What happened to the seed without water? Without light?
3. Why do plants grow toward the light?
4. If you were a plant, what would be the hardest thing about getting what you need?

What they are learning

This activity reinforces the Plant Parts & Needs lesson: every part of a plant has a specific job, and plants need water, light, and warmth to grow. By running a controlled experiment with four conditions, your child is also learning the most important skill in science — changing one thing at a time and observing what happens.