🫘 Do bigger seeds sprout faster?

My hypothesis

If I change how big the seed is, then how many of the five seeds have sprouted by day four will ______, because ______.

🔊 You fill in the blanks. Think about how much water a seed has to soak up before it wakes, and how much seed there is to soak. A guess is a good because: the test finds out.

Change, measure, keep the same

Scientists call the thing you change the independent variable and the thing you measure the dependent variable. The things you keep the same are the controls: if one of them changed too, you wouldn't know which change made the difference. Try each of the 3 levels 3 times.

What you need

• 🫘 Dried beans in three sizes: lima, pinto and lentils: 15 of each kind
• 🛍️ Plastic bags: 9 zip bags
• 🧻 Paper towels
• 🚰 Water from the tap
• 🩹 Masking tape, to mark lines
• 🖍️ Crayons or markers

Steps

1. Fold a damp paper towel into each of nine zip bags.🔊
2. Label three bags lentil, three pinto and three lima.🔊
3. Put five seeds of the right kind on the towel in each bag.🔊
4. Zip each bag almost shut, and tape all nine to a wall in one warm room, out of direct sun.🔊
5. Every day, add a few drops of water to any dry towel, and tell a grown-up if a bag smells bad.🔊
6. Every day, count the seeds in each bag with a little white root poking out.🔊
7. On day four, write each bag's count in your table.🔊
8. Keep counting until day seven, and note which kind sprouted all five first.🔊
9. Find the mean count for each seed and draw a bar graph.🔊
10. Wash your hands after touching the seeds, and never eat them.🔊

Every step is one you can do yourself, with a grown-up nearby. Write each number down straight away, in the table below, so nothing is lost.

Your results table

From 4th grade, add the tries for each level and divide by how many there were: that's the mean, and it goes in the last column. Then draw a bar graph, one bar for each thing you tried.

Why it works

🔊 A seed wakes up only when water soaks in and swells it. A small seed has less to soak through, so it can be ready sooner, while a big seed holds more food and may need longer. Each kind of plant also has its own wake-up speed, so size is only one clue.

Going further (7th and up): Change a second thing: soak each kind overnight first, and graph how the soaked seeds compare with the dry ones.

Board layout

This project at your grade

From 4th grade up, the table gets a mean column. See every project for 3rd grade, or print a blank results table.

What a judge will ask

• What did you change, and what did you measure? I changed how big the seed is and measured how many of the five seeds have sprouted by day four, in seeds sprouted, of 5.
• What did you keep the same, and why does that matter? I kept five seeds in every bag and the same damp towel in every bag the same, so the only difference was how big the seed is.
• How many times did you test it? 3 times at each of my 3 levels.
• If you did it again, what would you change or test next? I'd soak each kind overnight first, and graph how the soaked seeds compare with the dry ones.

Make it yours

Keep this project on this device and Peabody counts down to your fair day, with a plan for each day. Nothing is sent anywhere.

Try next

• 🫘 Do soaked beans sprout faster?2nd–6th grade · 7 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
• 🫘 How much water do bean seeds need to sprout?2nd–6th grade · 10 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants