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Sent in by:
Rebecca and Anna of Longview, TX

A biodome is a container for growing plants that doesn't need watering. Can you make one? We'll show you how.

Materials Needed

  • 3 two-liter soda bottles
  • 1 bottle cap
  • thick string
  • scissors
  • thumb tack
  • potting soil
  • something to plant
  • tape



  1. Check with a grown-up before you begin. Cutting soda bottles can be pretty tricky.
  2. Start by removing the labels from 3 two-liter soda bottles.
  3. First, cut the first bottle 2 to 3 centimeters above the top curve and then cut off the bottom of the same bottle 2 to 3 centimeters below the bottom curve.
  4. Cut the top off the second bottle 2 centimeters below the top curve.
  5. Cut the bottom off the third bottle 2 to 3 centimeters above the bottom curve.
  6. Poke a hole in one cap with a thumb tack and enlarge it with scissors so you can get the string through. Attach the cap to the remaining top. Soak the cotton string in water and run it through the hole in the cap. The wick draws water into the soil.
  7. Invert the capped top into the remaining bottom.
  8. Slide the cylinder into it, and add the short top as a cover.
  9. Fill the bottom part with water until it touches the cap.
  10. Add soil in the capped section but make sure that the string runs up into the soil and is not stuck along the sides.
  11. Now you're ready to plant and watch things grow.
  12. Poke a 2 centimeter deep hole in the dirt and drop in a seed.
  13. Cover the seed with some dirt.
  14. Add a little water until the soil is moist.
  15. Put the cap on and your biodome is all set. Everything your plant needs to live is in there! It's got nutrients in the soil, lots of air in the bottles and water that gets soaked up through the string. All you need to do is find a sunny spot to put this because plants need sunlight to make their own food!

Some of your Results

Eva, age 11 of Teaneck, NJ wrote:
We experimented in my 2nd grade class to see what would happen and it worked

Alice, age 7 of San Francisco, CA wrote:
it was so cool I did it with my sis.

Imole, age 5 of UK wrote:
The plant grew very well in four days.

Toluwa, age 8 of UK wrote:
I grew a black eyed pea and it worked it even grew some black eyed peas.

David of UK wrote:
i planted it easily but when it grew it was tall but its roots were eaten through by green fly so it died

Sam, age 11 of HI wrote:
it was very fun because I did it in my 3rd grade class

Rhiannon, age 10 of Columbus, OH wrote:
Well, I didn't really do it at home. In my science class last chapter, we made terriums. We put in cooking oil, vineger, dish soap, and somthing else that I can't rember off the top of my head. We did that to resemble either an Oil Spill, acid rain, and at least kitchen waste. We made a classroom control to see how the others had a benificial, detrimental, or nutral effect. Sadly I was overcome by the terrors of a cold and was absent the whole time we did it. I was there for at least a week after we did it so I kind of know how it turned out. My group chose acid rain for our tragidy. Ours, before I left, was doing o. k., but it looked like it was about to drop pretty soon.!!

Charle, age 12 of Dover, NJ wrote:
The plants, roses grew.

Sonya, age 8 of Prescott, AZ wrote:
I made a Biodome for my science project and planted Alyssums. In 3 day I had sproutling and in 14days they were over and inch tall. I got a A in science and won 1st place inthe science fair at school. A teacher said that I shoud enter the regional fair. I think I got to give it a try. My friends at school also liked my project.

Jerimiah, age 5 of Chicago, IL wrote:
Nothing grew except for the seeds.

Michael, age 13 of Chicago, IL wrote:
When I first added the seeds it only lasted about three hours till the seeds grew! I got an A+ on my project.

Abigail, age 10 of Houston wrote:
As soon as I saw it on the show I wanted to do it. I planted some beans and in about three days little plants came out.

Catherine, age 11 of Dallas wrote:
Well I did this project for my science fair project. I also put extra details in my biodome. I put bugs and fruit seeds in my biodome. I won second place at the science fair.

Tori, age 12 of Keswick Ridge, NB wrote:
Mine worked so well the plant grew out of the biodome. Its so cool!

Zoom Fan wrote:
Well I have done it before and I didn't do it with a lid of water at the bottom, Instead I poured water over the dirt. After a few days when my bottles ecosystem made clouds and rained. It was really cool!

Alyssa, age 12 of Chandler, AZ wrote:
Well I did the biodome for a science project and I on ly had 8 days. By the 3rd day my marigolds were already growing. But on the 8th day they were as tall as the ones in the photo. But mold was growing so they died.

Reggie, age 10 of Dublin, CA wrote:
When I planted limabean seeds it grew over 6 inches and the pea seeds diddn't grow. Later, mabey next mont, I'm going to do it for the science fair.

Reggie, age 10 of Dublin, CA wrote:
Well, mine hasn't grown yet, but I noticed that when it rained I still got condensation. So I guess it's weather changing! I hope it grows.

Jasmine, age 12 of Markham, ON wrote:
In the first place I made a biome out of two plastic bottles first I cut the top off then I took the other bottle and cut the top off too. Then I 'put mud and sand inside the base of the bootle and took the top and put the cap side under and taped it then I took some mud and planted seeds. Then I took the cap and sticked it on the top. After three days my plants grew and then I put salt mixed with hot water and then watch it.

Justin, age 8 of North Haledon, NJ wrote:
Its working great! I'm getting some sprouts.

Nikita, age 9 of Whittier, CA wrote:
It worked exactly like yours. I saw a lot of mold. It was awesome when the mold started to turn black.

Vivian, age 10 of San Jose, CA wrote:
I did it for my science fair project and it grew the day after. It was very cool to do the project.

Nini, age 12 of Tacoma, WA wrote:
I got mold. I thought it was pretty awsome, now its black. I cant wait to see the next phase.

Michael, age 11 of St. Louis, MO wrote:
I planted a couple different plants. Some kid dropped my biodome but my plants still survived.

Stephanie, age 10 of Tucson, AZ wrote:
It really worked. I think I want to tell my friends about it. My plant sprouted.

Whitney, age 13 of Brooklyn, NY wrote:
I chose the biodome for a science fair project to see if a plant can grow better in a biodome or in a pot. (I CHOSE A BEAN SEED TO GROW IN THE BIODOME AND A POT.) My research show that a plant grow better in a biodome then a pot. So I challenge you Zoomers to use a different seed and grow it in a pot and a biodome. Have fun!

Melissa, age 10 of Telford, PA wrote:
Nothing grew. Except mold.

Larry, age 11 of Kennewick, WA wrote:
I made a biodome in class and we had fun with it. We go to watch as they grew. I grew parsley and I got to see it go through the differnt stages.

Lauren, age 11 of Hot Springs, AR wrote:
I tried the biodome and it worked really well. My plant was happy and healthy. I used a baby bleeding heart from my grandma's garden. But it died because it got cold.

Andrea, age 10 of Hazel Green, AL wrote:
I tried it with my class and we put misquito, fish, snails, and plants and it worked out great. Maby if kids told there teachers about it, they will get to have that wonderful experence.

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