4-H Canada Blog

Three Fun Science Experiments to Try this Summer!

Are you and your 4-H friends curious about the world around you? If you like being creative, solving problems and exploring new ideas – then you have the characteristics to become a great scientist! Check out these three awesome science experiments to try with your club this summer.

Activity 1: Exploding Watermelon

Yummy fruit and (safe) explosions – make sure you try this experiment outside!

You’ll need:

  • Watermelon
  • LOTS of elastic rubber bands
  • Safety glasses


  1. Put the watermelon outside or on a counter where you can make a mess.
  2. Put on your safety glasses Safety is always important in science…even when trying fun fruit experiments!
  3. Predict how many rubber bands you think it will take to pop the watermelon.
  4. Have a friend, leader or parent hold the watermelon steady while you place the rubber bands around the middle of the watermelonWhat changes do you see?
  5. Keep adding elastic until the watermelon starts to form deep cracks. Then stand back and wait for the explosion!
  6. Suggestion: Eat the watermelon after it explodes!

Here is a video of the experiment:

Take it further:

  • Can you do this with other fruit?
  • Does the size or number of rubber bands matter?





Activity 2: Rock Crystal Candy

In the mood for something sweet? Make your own candy by watching sugar crystals grow. How long will you wait before doing a taste test?

You’ll need:

  • 1 cup of water
  • 3 cups of white sugar
  • Clean glass jar
  • Pencil or butter knife
  • String or yarn (made of cotton or wool – avoid nylon)
  • Saucepan
  • Spoon
  • Food colouring (optional)


  1. Tie the string to the centre of your pencil or butter knife.
  2. Place the pencil/butter knife over the mouth of the jar, with the string hanging inside..
  3. With adult supervision, bring water to a boil in the saucepan.
  4. Stir in the sugar, one spoonful at a time. You want to make sure all of the sugar dissolves before you add the next spoonful. If you don’t, the sugar crystals will form in the jar and not on your string.
  5. Carefully pour the syrup from the saucepan into your clean glass jar.
  6. Balance the pencil or butter knife (with the string tied to it) on the edge of the jar and let the string dangle into the syrup. Make sure the string isn’t hitting the side or bottom of the jar.
  7. Find a safe spot for your jar so it won't get knocked over or get dust in it and allow 24 hours for it to crystalize.
  8. When the crystals stop growing…or you just can’t wait any longer, take the string out of the jar and let the candy crystals dry. Did you see how the crystals formed?
  9. Once it’s dry, enjoy your sweet science treat!

Take it further:

  • FUN IDEA Want some colourful candy? Add a drop or two of food colouring.
  • What would the results be like with brown sugar? Maple syrup?
  • What happens if you put the jar in direct sunlight versus in the dark?
  • Could you add flavouring?

Activity 3: Design Your Own Sprinkler

Want to cool down this summer? Create your own sprinkler system and share your designs with us online on our social media by tagging @4HCanada to your Facebook, Twitter or Instagram posts.

You’ll need:

  • Outdoor hose
  • Electrical tape
  • Plastic bottles
  • Scissors


  1. Take a plastic bottle and carefully make holes in the bottle with scissors.
  2. Tape the mouth of a plastic bottle to the end of an outdoor hose and slowly turn the water on. Use more tape to fix any leaks. What happened?

Take it further:

  • Change your design as you go – add straws, balloons, funnels, tin foil, more bottles, more hose…whatever you want! Keep testing it to figure out how to make your design even better!
  • What happens when you add more holes to your sprinkler system?
  • How far can you make your sprinkler go?
  • When watering plants or your lawn, what time of day is best for running a sprinkler?

Did these experiments keep you cool and get you thinking like a scientist? Science is all around us; let your curiosity be your guide and discover many more fun and safe experiements this summer. Learn more about how other 4-H’ers used science to try something new, visit the 4-H Canada Science Fair web page.

Be sure to tag @4HCanada on your Facebook, Twitter and Instagram posts.