What Do Plants Need? Investigation

My students are crazy about science investigations this year! This week, we started a plant investigation called "What Do Plants Need?" It is a two week long investigation that allows them to observe changes in plants that are getting different things. Basically, you use 6 plants (I try to pick flowers that I know will easily die!) and plant them in pots or cups. One flower gets no sunlight, one gets no soil, one gets no water, one gets no space, one gets no air, and the last plant gets everything. My students LOVE planning the experiment and coming up with ideas for what we can do to the plants. (I actually feel kind of guilty knowing that we are killing them... but it's all about the learning, right?!) Here are some pics of the plants and how we planned the investigation:

 
Plant #1 (No light): We decided to put the plant in the cabinet behind my desk. I pushed the plant about as far back as it could go and keep the doors closed (as much as possible!)

Plant #2 (No soil): The kids thought that I should not only remove all of the soil from the roots but also rinse off the roots to get every speck off. I did just that... and boy, is this plant dying already!

Plant #3 (No water): This one was simple- don't water the plant. I asked them how we could remember not to water this one and one of my students suggested making a sign to remind our "plant caretaker" not to water it at the end of the day. (Yes, the sign says "member"!)

Plant #4 (No space): This was kind of a difficult one for them to brainstorm, but they ended up deciding to put the plant in a small dixie cup instead of one of the blue SOLO cups. Later, we also added some rocks and gravel to the top so the plant doesn't have any space to grow.

Plant #5 (No air): This poor plant gets no air at all. My students thought that we could zip it up in a Ziploc baggie and only unzip it to water the plant at the end of the day. This one is fading fast too!

Plant #6 (Gets everything): This plant gets everything that it needs to survive, so we simply set it in the window and plan to give it everything.

We planned the investigation on Monday and then observed the plants today (at the end of Week One). I put one plant at each table and allowed the kids to look closely at it, feel the soil, etc. They recorded their observations and then rotated to the next table. They did this for all 6 plants. Next Friday will be the last day of the investigation. We will observe them for the last time and then write about our conclusions and what we learned. Hopefully the plants cooperate =) The kids are so excited about this investigation!