What Do Plants Need To Grow?

By Morgan Turano, science editor

Grades 2 & 3 Science experiment: For students

More in this series
If you want to help your child, use our version for guardians. Also we provide a Spanish version.

Part 1

Introduction

What do plants need to grow? Do they need water? Do they need sunlight? How can we know? We can do some tests.

WANT TO HELP YOUR STUDENT?: Victory has created a guardian version of this lesson so that parents and guardians can provide guidance | A printable version of this lesson is also available

Test 1

Do Plants Need Water?

How can we test if plants need water? We can grow two plants. We can give both plants sunlight. We can give one plant water. We can give the other plant no water. Then we can watch to see which plant grows.

What You Need

• 2 heads of celery
• 2 jars
• Water
• Permanent marker
• Ruler
• Paper
• Pencil
• Tape

Set Up

Step 1. Get two jars. Label them A and B.
Step 2. Ask an adult to draw a line around jar A.
Step 3. Ask an adult to cut two heads of celery.
Step 4. Rinse the celery ends in water.
Step 5. Stand the celery ends in the jars. Add warm water to jar A. Do not add water to jar B.
Step 6. Place the jars in a sunny window.
Step 7. Change the water in jar A every day.
Step 8. Record what you see every day.

 

Your Notes

Write or draw what the plants look like every day.

 

Day	Jar A: Plant With Water	Jar B: Plant Without Water
1
2
3
4
5
6
7

 

What Does It Mean?

You have finished your test. You recorded what you saw each day for seven days. But what does it mean? You can answer questions to find out!

1. Did the plant in jar A grow?
2. Did the plant in jar B grow?
3. Which grew more, the plant in jar A or jar B?
4. Do plants need water to grow?
5. How do you know?
6. What do you think will happen if you keep giving jar A water every day?
7. What do you think will happen if you take the water out of jar A and do not add more water for a week?

Part 2

Test 2

Do Plants Need Sunlight?

How can we test if plants need sunlight? We can grow two plants. We can give both plants water. We can give one plant sunlight. We can give the other plant no sunlight. Then we can watch to see which plant grows.

What You Need

• 2 heads of celery
• 2 jars
• Water
• Permanent marker
• Ruler
• Paper
• Pencil
• Tape
• Cardboard Box

Set Up

Step 1. Get two jars. Label the jars A and B.
Step 2. Ask an adult to draw a line around each jar.
Step 3. Ask an adult to cut two heads of celery.
Step 4. Rinse the celery ends in water.
Step 5. Stand the celery ends in the jars. Add warm water to both jars.
Step 6. Place jar A in a sunny window. Place a box over jar B.
Step 7. Change the water in the jars every day.
Step 8. Record what you see every day.

 

Your Notes

Write or draw what the plants look like every day.

 

Day	Jar A: Plant With Sunlight	Jar B: Plant Without Sunlight
1
2
3
4
5
6
7

 

What Does It Mean?

You have finished your test. You recorded what you saw each day for seven days. But what does it mean? You can answer questions to find out!

1. Did the plant in jar A grow?
2. Did the plant in jar B grow?
3. Which grew more, the plant in jar A or jar B?
4. Do plants need sunlight to grow?
5. How do you know?
6. What do you think will happen if you keep giving jar A sunlight every day?
7. What do you think will happen if you place a box over jar A for a week?

Additional questions for Grade 3:

8. Imagine you had a plant. You placed it in a sunny window. You watered it every day. Then you forgot to water the plant for a week. Do you think the plant would grow taller that week? Why?

9. Imagine you had two plants. You placed them both in a sunny window. You watered them both every day. Then you moved one plant to a room with no windows. Which plant do you think would keep growing taller? Why?

10. Can you make a plant grow taller by changing the amount of sunlight it receives?

11. Can you make a plant stop growing taller by changing the amount of water it receives?

12. How does the environment affect a plant’s traits?

MORE FUN LESSONS: Find out how to make a solar cooker | Read all of Victory’s sample lessons that guardians can do with their children