Lernin' Stuff · Project 2

Plant Bubbler Lab

Kids turn dollar-store finds into a bubbling root jar, then run a real experiment: do plant cuttings grow roots faster when their water gets extra oxygen?

Credit where it's due

This project is based on a DIY propagation bubbler idea by Xposur Botanica (@xposurbotanica). We turned their idea into a hands-on science lesson. Go give them a follow.

View this video by @xposurbotanica on Instagram

Watch the original video

Ages

6 to 14, with a parent or guardian building alongside. Adults handle the scissors and the plug.

Schedule

One day. Build it in class, take it home, and send us a photo of your roots every 7 days.

Cost

$10 suggested donation. Scholarships available for any family who needs one.

Take it home

Every family takes their bubbler and cuttings home to keep growing and keep checking.

The science

Roots breathe. They pull oxygen out of the water around them, and a cutting sitting in still water can use it up. Bubbles push fresh air into the water and keep it moving, so new roots get more oxygen while they grow.

The experiment: set up two jars with the same kind of cutting. One gets bubbles, one doesn't. Everything else stays the same: same light, same water, same day. Take a photo every 7 days and compare.

Which jar grew roots first?
Which has more roots, and longer ones?
Did the water in either jar get cloudy or smelly?

Kids learn what a variable is, why scientists keep everything else the same, and how to measure and record results.

What you need

🌱Glass vase: About $1.75 at Dollar Tree. Plastic works too for little hands.
🌱Metal mesh pencil holder: About $1.25 at Dollar Tree. Sits on top and holds the cuttings up.
🌱Small aquarium air pump: The kind used for fish tanks.
🌱Airline tubing: Long enough to reach from the pump to the bottom of the jar.
🌱Air stone: Breaks the air into tiny bubbles.
🌱Check valve (our tip): A tiny one-way valve for the tubing so water can never run back into the pump.
🌱Plant cuttings: Pothos, coleus, tradescantia or Mother of Thousands pups all root well in water.

Build it

1
Set up the jar
Rinse the vase and fill it about three-quarters with room-temperature water.
2
Run the air line
Push the air stone onto one end of the tubing and drop it to the bottom of the jar. An adult adds the check valve to the tubing, arrow pointing toward the jar.
3
Add the holder
Set the mesh pencil holder into the top of the vase so it rests above the air stone.
4
Take your cuttings
With a grown-up, cut stems just below a node, the little bump where leaves and roots grow. Pull off the bottom leaves.
5
Plant them
Slide the cuttings through the mesh so the nodes sit underwater and the leaves stay dry.
6
Turn on the bubbles
Place the pump higher than the water line, plug it in, and watch the bubbles start.
7
Watch and record
Every 7 days, measure the longest root, count new roots, and snap a photo of the jar. Email it to info@thechurchofmanyhands.org. Plants only, please, no faces.

Safety first

Water and electricity: the pump always sits outside the water and higher than the jar. Grown-ups plug it in.
Glass can break. Younger kids can use a plastic jar instead.
Some houseplants can upset a stomach if chewed. Keep cuttings away from pets and small children, and wash hands after.

Want in on the next Lernin' Stuff build?