The other day I walked into my kitchen to see the kids a little too close to the trash can for my comfort level, so I asked what they were up to.
“We’re observing!” my four year old said brightly.
Oh no… What in the world could they “observe” from a trash can?
“I want to see if something will grow!”
I’m okay with a lot of gross science experiments, but digging around the trash can? Not my favorite thing.
I knew I needed to find an activity that would feed that curiosity and love of “grossness”, and thankfully I came up with this super fun bacteria gardens gross science for kids!
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Bacteria Garden Gross Science for Kids
If you’re looking for gross science experiments, you cannot get much grosser than this one!
Kids will love watching how bacteria and mold can grow right before their eyes, even if they don’t have a microscope to see it.
Please note: Since this activity is all about cultivating bacteria and mold, children should NOT open the containers after their gardens are completed. Children should wash their hands after handling the agar plates.
How to Grow a Bacteria Garden
There are two ways to start your agar plates. You can either purchase pre-made agar plates for a truer, cleaner experiment or make your own agar plates like we did.
Just know, if you do make your own agar plates this way, your “bacteria” garden will be more of a mold garden due to contamination.
You will need:
- Small clear containers with a lid (or pre-made agar plates like with this science kit)
- Chicken broth
- Cotton swabs
- Green food coloring (if you make your own agar)
- Xanthan gum (if you make your own agar)
Boil the chicken broth in a pot. Add a few drops of food coloring and sprinkle in some Xanthan gum. Mix until all clumps are gone and the mixture is thick.
Allow to completely cool.
Label a container with each child’s name.
Have the kids swab their tongues (told you this was gross science!) with the cotton swab and rub it onto the surface of the agar plates in whatever design they want.
Close the lid and place on top of the refrigerator.
Wait 1-2 weeks.
Pull down the “bacteria gardens” and see what’s growing!
In our bacteria gardens, we had two drastically different results. In garden one, mold had taken over. But in garden two, bacteria was growing strong!
The kids noted that the bacteria had much more interesting shapes than the mold.
Looking for more STEAM (Science, Technology, Engineering, Arts and Math) projects and inspiration?
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