Have you heard about Kids' Extra? It's a fun publication for elementary school-aged children that's filled with recipes, art activities, games, science experiments and more. Look for it in your Richmond Times-Dispatch on the first Sunday of every month!
Spring Is Here!
It's spring! The days are getting longer and warmer — and wetter! Look closely at the ground — do you see any young plants growing?
Here are some experiments you can do to get you thinking about plants; how they grow and what they need.
Bean Bags
You'll need
- Bean seeds – you can use dried beans from the grocery store; lima beans work well.
- 4 plastic zipper-type sandwich bags
- 8 paper towels
- A marker
- Water
- Tape
- A box
Steps
- Stack two paper towels together. Fold them in half, then in half again. Put the folded paper towels, flat, into a sandwich bag. Repeat this with the other bags.
- Put four dried beans into each bag. (In this experiment, you are keeping some things the same for all of your bean bags. Scientists call things that stay the same in an experiment constants. Some of your constants in this experiment include the type of beans and the number of paper towels. What is another constant?)
For this experiment, you will change the water and the light for your bean bags.
Use the marker to label each bag: - Water and Light
- Water and No Light
- Light and No Water
- No Water and No Light
- Add enough water to bags #1 and #2 to completely soak the paper towels. Do not add any water to bags #3 and #4. Zip all four bags closed.
- Bag #1 has water, bag #3 has no water… but they both need light! Tape bags #1 and #3 to a window so sunlight can shine on them.
- Bag #2 has water and bag #4 has no water, but they both need to be kept away from the light. Put bags #2 and #4 inside the box so no sunlight will shine on them.
- Each day observe your bean bags to see what is happening to the bean seeds. Are any germinating – starting to sprout? Look for the tiny root poking out of the seed coat - the outside of the seed. Use the bean bag chart to record the number of seeds that have germinated in each bag. Remember to put bags #2 and #4 back in the box after each observation!
Things to think about
You changed the water and the light. Which one was most important for the bean seeds to germinate?
Do you think a bean seed would get sunlight when it is planted under the soil?
Here is a challenge: How could you design an experiment to see if temperature is important for bean seeds to germinate?
Do you think other types of seeds might have different needs? Did you know some types of seeds need heat from a forest fire to crack their tough seed coats before they can germinate?
To see your germinated bean seeds grow into bean plants, carefully open the bags and plant the bean sprouts, paper towels and all, in a pot of soil or in your yard. Remember, plants need both sunlight and water to keep growing!
| How many bean seeds germinated? | |||||
|---|---|---|---|---|---|
| Bean bag: | Day 1 | Day 2 | Day 3 | Day 4 | Day 5 |
| # 1: Water and Light | |||||
| # 2: Water and No Light | |||||
| # 3: Light and No Water | |||||
| # 4: No Water and No Light | |||||
After you’ve tried the Bean Bags experiment, try this new version to see if plants know up from down.
Upside
Down
You’ll need
- Bean seeds – you can buy a bag of dried beans at the grocery store; lima beans work well.
- A jar or cup
- 4 plastic zipper-type sandwich bags
- A marker
- 8 Paper towels
- Water
- Tape
- Pencil and paper
Preparation
Place some bean seeds in a jar and cover them with water. Place the jar in the refrigerator overnight.
Use the marker to label your four bags: #1, #2, #3 and #4. Draw an arrow pointing from the bottom to the top of each bag.
Steps
- Follow steps 1 and 2 from “Bean Bags” above, using the soaked beans from the refrigerator. What are your constants?
- In this experiment, you will also have water as a constant. We know that seeds need water to germinate. Add enough water to each bag to soak the paper towels. Zip the bags closed.
- You will also have light as a constant. Seeds can germinate without light, but it is easier to make observations if you can see the seeds. Use tape to attach your bags to a window where you can observe them. Make sure that the arrows are pointing up.
-
Each day, observe your bean seeds and record their growth. Remember to label your drawings.
Observations
How long did it take for the beans to sprout?
Which part of the plant grew first? In which direction did it grow?
What part of the plant grew next? In which direction did it grow?
- Once your young bean plants have roots and shoots showing, carefully remove bag #3 and bag #4 from the window. Turn these two bags upside-down, so the arrows point down. Tape them to the window again. Now these plants have roots up and shoots down. What is your variable – what did you change?
-
Continue to observe your plants and record their growth.
Observation
Do the “upside-down” plants stay “upside-down”? In what direction do the roots and shoots grow?
Things to think about
Why do you think it was important to moisten the paper towel?
Why did the roots grow first?
For Your Information
When a seed begins to germinate, it absorbs water. The water makes the seed swell and makes it easier for the developing plant to grow.
Usually, the roots develop first, helping to anchor the young plant in the soil. The roots also absorb the water and nutrients which the developing leaves need to photosynthesize. The bean’s roots will grow downward no matter how the bean is positioned when it is planted. The roots of plants respond to Earth’s gravity, and grow towards the pull, in the “down” direction!
The shoots respond to gravity by growing away from gravity's pull. This makes "shoots grow up while roots grow down."
New Plants
You probably know by now that many plants grow from seeds. But did you know that by cutting off small sections of certain plants, such as their roots, stems or leaves, you can grow a new plant? The new plant had only one parent plant and is an exact genetic copy of the original plant – it is a clone!
The process is called "cutting," and it works especially well with ivy, zebra plants, coleus and spider plants.
Look around your yard, and check your houseplants, to find good plants to take cuttings from - but make sure to ask before cutting anything off!
You'll need
- Plants to take cuttings from (remember to ask first!)
- Scissors
- Clean, empty glass jars
- Water
- Potting soil
- Flowerpots
Steps
- Carefully cut 4-inch pieces from each original plant. Make sure that your cuttings have at least a few leaves on them.
- Place each cutting in its own jar. Fill the jar most of the way with water.
- Place the jars on a sunny windowsill. Add more water whenever the level gets low.
-
Observe your cuttings. If your clones are successful, you will begin to see tiny new roots growing from the cut ends of the stems.
Observations
Did all of the cuttings live?
Did all of the cuttings develop roots at the same time, or were some plants faster?
Did one type of plant make better clones?
- In a few weeks, when a cutting has grown roots that just about fill the jar, it is time to put your new cloned plant into its own flowerpot. Fill a flowerpot with potting soil and gently plant your clone. Place the pot on a sunny windowsill to grow. Water whenever the soil is dry to the touch.
More Web Resources
Check out this experiment kids did to see if changing the color of light would affect bean-seed germination!
Visit the Junior Master Gardener Web site for more cloning experiments!
Visit Global Garden. It's full of gardening crafts, projects and experiments to try.
Watch a time lapse video of plants germinating and growing
Plastic bag experiment illustration by Tod C. Parkhill.