Thursday, August 18, 2011

Plant in a Bottle

I took a life science class for educators this summer in upstate South Carolina and one of the inquiry activities we did was with a plant in a jar.

The question we were asked was how long could a plant live in a closed container. We had to come up with a hypothesis and then support our claim. Some people could not make a hypothesis without more information and we wrote those questions on our flip chart paper, i.e. How fast does a plant use up oxygen?

We then planted small plants inside a plastic container (think Glad Ware) and marked the date on the outside. We were told to keep them out of direct sunlight and not to open them until we came back for our follow up class (a month later).

Sadly most of our plants died. My plant died because the leaves started touching the sides and became water logged. Others died because they spent the month in direct sunlight or got rolled around in the back of their car :) The professor said it was the first time he used the glad ware containers (due to the cost involved in the project) and had never seen so many plants die before. He then showed us a plant he has had in a closed jar in his office for four year (see last picture).

I thought this was a great inquiry project and one I could easily make a year long. We start with inquiry (where we would set up the project) and then move on to weather. In our weather unit we can use the experiment to illustrate the water cycle and transpiration. We then move on to our light unit and we can talk about how light behaves when it hits transparent and translucent objects like our container (in fact you could try different containers and see if that makes a difference). In our astronomy unit we can talk about how sunlight effects growth and in our organisms unit we can use the project to highlight what is needed in a habitat. At the end of the year students can take their plants home.

I know this project could get pricey but i thought it would also make a good grant project.


mer said...

found my way here from pintrest. i'm an english teacher/literacy coach. looking forward to exploring your site and sharing it with teachers at my school.

Karen said...

Just discovered your great blog and am spending some time going back...I just had to tell you that we had a terrarium in a gallon jar once that lasted 8 years. It was planted by a girl in 4th grade, stayed in my classroom year-round, and when she was a senior, our janitor hit it with his elbow and knocked it off our window ledge and broke it. So sad. We never took the lid off in those eight years. I always wondered how the soil had enough nutrition left, and the kids always wondered where it got enough carbon dioxide. I guess the lid must have allowed some gases to exchange??? Anyway, true story, even though I can't explain all the science. Thanks for all the good ideas you share! Karen from NE

Sally said...

This is such a great idea! I Would love to do this in my 4th grade classes this year. Any tips that you could give about type of plant, soil, etc? Is the glass jar a gallon size container or is it larger? I would love to write a grant to fund this project! Thanks for your info!

Sally said...

I really enjoyed reading this post. I would love to do this in my 4th grade classes this year. Do you have any advice that you would give me about type of plant, soil, size of jar? Any more info would be greatly appreciated.

Cathy S. said...

You don't need a grant to do this project. You can use the clear plastic containers that many kinds of food come in. Some will have a more airtight seal if that is important to you, but all of them will work for having a terrarium. I think you can try most any type of plant except succulents (just guessing they wouldn't do well). One of the most important things is how much water you start out with. There's no way to give a precise amount to use. If the walls of the container are heavily covered with water drops after a day or two then you may have too much water. But you can just open it up and take out a little water. Generally you want to start with well watered soil, but not soggy. If you don't have a decent amount of water condensed on the container after it's been closed a day or two then you probably didn't put enough water. If you use a very loosely "sealed" container (like the containers cookies come in, in grocery store delis) you will either have to seal the container with tape or add water every now and then. Ferns are definitely ok for terrariums. Some kinds of moss are ok, but you can also run into problems with mold. And definitely never let the container be anywhere near direct sunlight - great lesson there on the greenhouse effect. Play around with plants from your yard before you start your project.