Plant Growth Experiment

Student scientists have developed an excellent understanding of the scientific method and how it is employed through our inquiry into decomposition. Over the past two weeks classes have been collecting background research and building understanding through exploration via our Plant Inquiry website and through interacting with horticulture expert Kathleen Smythe. Over the next month they will have the opportunity to use their skills as researchers and new knowledge to conduct an authentic experiment establishing which variables have an effect on plant growth and changes and to what extent. As students have been individually involved in background research prior to designing this experiment, the expectation is that the research that has been done will find its way into the observations and conclusions that result. This site will serve as a resource for students as they work their way through this new scientific exploration.

Pre-step - Group selection
Please go to this link to help select the group you will collaborate with for this science experiment and what you will be researching. Once you have finished, please help us make a comprehensive list of the vocabulary that should be included in our plant experiment documentation. This should be vocabulary you have come across through background research and interaction with experts. Share your vocabulary by adding it to this Google Doc.

Step 1 - Experiment Proposal

Step 2 - Designing the Experiment
Once proposals have been approved, students will work together in groups to build a google document which will contain their planning for the experiment. Included in this document will be:
  • A clearly stated Problem
  • Hypothesis
  • Variables (established in previous step)
  • Materials required
  • Daily Procedures
Students will also build a chart which will include space for the observations they plan to document. This chart can be built in a google document or spreadsheet but should include space for:
  • Qualitative Observations including written notes and photos
  • Quantitative Observations including space for numerical measurements (depending on their responding variables)
Here are links to our groups google documents:

4.1/4.3 Labs

4.2/4.4 Labs
Group 12  Aryan, Kyra, Maya

Step 3 - Scientists at Work
Over a 2 and a half week period, students will conduct their experiment, while documenting changes they observe on a daily basis. Observations must demonstrate the background knowledge students have gained through use of appropriate plant specific and scientific vocabulary.
Click here to access observations of control plants updated by Barkley.

Day 1 Procedures:
  1. Gather plant and add 150 mL of water to plant.
  2. Document starting point observations (photo, qualitative and height measurement from first branch to top of the stem)
  3. Replace plant in sunlight
Day 2 Procedures:
  1. Saturate plant with 100 mL of water.
  2. Collect pot or pots and labels. Stick labels to outside of pots that plant(s) will be potted in.
    • Groups planting outdoors will begin constructing plant cozies as per instructions (link). They can also begin working on updating observations (see step 7) while they wait for Mrs. Park to head outdoors with extra soil, spades and plant cozies.
    • Groups planting in topsy turvy will begin updating observations (see step 7) while they wait for Mrs. Bower to help them plant their tomatoes in the Topsy Turvies as per instructions on the box.
  3. Fill bottom of pot with 1 cup of bagged soil.
  4. Place plant along with biodegradable pot carefully into the new pot.
  5. Cover plant and biodegradeable pot with new bagged soil* 
    • Groups testing plant in decomposition soil need to cover plant with decomposition soil not bagged soil.
    • Groups testing soil compaction need to compact soil gradually as they add it to their pot.
    • Groups testing fertilizer need to add 2 tbsps of fertilizer to top of soil before adding water.
  6. Once plant is covered with soil to 1 inch below surface of pot, ALL groups add water. Standard amount of water is 250 mL.
    • Extra water amount is 500 mL
    • Less water amount is 100 mL
    • Groups adding different temperature water need to measure 250mL of hot or cold water
    • Groups adding sugar or salt need to mix 1 tbs of either into 250mLof water before giving to plant.
  7. Once plants have been potted and watered, begin Day 2 observations by recording any details you might have missed on Day 1 or changes that have occurred since initial planting. Take a photo of your plant with a blank background.
  8. Once you have finished updating your observations, continue to work on refining your presentation (update procedures and materials)  as necessary with the information provided today.
Plant experiment specifications:

    Standard H20 addition: 1 cup/250 mL a day
    Extra H20 addition: 2 cups/500 mL a day
    Almost no H20 addition: ¼ cup/65 mL a day
    Standard sugar addition: 1 tbsp a day (diluted in 1 cup of water)
    Standard salt addition: 1 tbsp a day (diluted in 1 cup of water)
    Blue light control: On at 9:00 am, off at 3:30 pm
    Fertilizer addition: 2 tbsp into top soil, water added on top
    Decomp addition: Combine soil remnants and mix with hands into pot

Step 4 - Drawing Conclusions
Students will be given choice as to how they might best present their data with some options including:
  • Keynote 
  • Prezi 
  • Glogster (one account, collaborate on the contributions)
  • iMovie (One group member will be responsible for an entire section, recorded and exported as an m4v file to their desktop. Files will be combined on one computer as a final product.)
  • Lab report (pages)
Step 5 - Self-Reflection
Please answer the following questions on a new blog post called "Plant Experiment Self-Reflection"
1. During this experiment, I learned the following 3 things about Plant growth and changes:

2. While working on this experiment, I was responsible for the following tasks:

3. Which task did you find most enjoyable? Why?  Which task did you find most challenging? Why?

4. Did you choose a good group to work with? YES/NO? EXPLAIN (please use the rubric below to help with your explanation)

5. If you could make the plant experiment even better, what changes would you make?

6. What has this experiment taught you about being a scientist?

7. Using the rubric below, please assess your work throughout this experiment.  Be sure to give yourself a mark and a comment for each. 
Strong Work in the Science Lab Rubric - Created by 4.1/4.2/4.3 and 4.4






I always have questions and make observations that relate to the rotting materials, the time, weight, temperature inside and outside

I commonly ask questions and makes observations  independently and they relate to the fruit and vegetable, time, weight, temperature etc.

I sometimes ask questions and make observations but other times I need to be reminded.

My teachers are always begging me to ask questions. My work lacks relevant observations.

Knowledge and Skills

I always show what I know about the specimen. I demonstrate good observation skills and am confident in the accuracy of my conclusions

I often show what I know and I usually make pretty good observations about the fruit and the changes that are happening to it. I am mostly confident about the accuracy of my conclusions.

I only show what I know when I am reminded to. I am not usually sure about whether or not my conclusions are accurate.

Mrs. Park and Mrs. Bailey have no idea what I know because I never show them, I just sit around. I never seem to have an idea about whether or not my conclusions are correct.

Enhancing and Supporting Community

I always make sure everyone gets a turn and is included. I compromise, talk respectfully and support other peoples ideas

I have a ‘you first’, ‘me last’ mentality. My body language communicates positivity.

I sometimes have a ‘me first’ mentality and forget to listen to, or cooperate with others.

I don’t help or communicate with my group members and I act like I don’t want to be there.


I am direct, expressive and scientific. I communicate my ideas simply but in detail.

I communicate my scientific ideas clearly.

I sometimes communicate my ideas but my group members need to prompt me.

I don’t really ever communicate, I sometimes just sit or I talk about other things.

Work Habits

I use strategies that help me complete my tasks in the required time. I always do exactly what I am supposed to be doing. My work is efficient and effective.

I  usually use strategies that help me complete tasks in the required time. I am usually doing exactly what I’m supposed to be doing and my work is good.

I sometimes fool around and I lack focus. My work inconsistent.

I basically don’t do anything, I just sit in desk and relax, not paying attention or talk about video games or playdates

Deirdre Bailey,
Mar 13, 2012, 10:46 AM