Croydon Schools Science Project (Wellcome Trust)
A23 Investigators: Science Transition Units –
Environmental Effects on the Growth of Plants
Lesson Plan Year 6
Topic: Environmental effects on the growth of plants
Lesson Title: Lesson 3 – Investigating variables that affect plant growth.
NB: This lesson is 1½ hours long, including 30 minutes for planting/setting
up the investigation. After this lesson there will need to be a gap of 2-3
weeks before the next lesson, whilst plants are growing.
Lesson objectives: To identify variables that might affect plant growth.
To learn how to plan an investigation of a variable that might affect
Learning outcomes: To appreciate plant biodiversity in the local environment and to
understand how the environment affects plant adaptation.
[This learning outcome applies to all lessons in this unit].
Success criteria: 1. I can discuss variables that might affect plant growth.
2. I can decide which variable to change.
3. I can decide how to measure whether the change has made a
difference to plant growth.
Key questions to help What variables do you think might affect plant growth?
challenge and support How? Why?
pupils’ learning: How might you change a variable?
How will you measure the change?
Starter: Discuss pupils’ ideas about things that might affect the way plants grow.
Show pictures of healthy/unhealthy plants:
Which plants are healthy?
Which are unhealthy? What has happened to them?
How can we make this plant healthy?
What do plants need to grow healthily?
Main activities: Plan an investigation of variables that affect the way plants grow.
Use “Post-It Note” planning to discuss variables:
Identify key variables that affect plant growth
Identify ways that you might measure how well a plant is growing
Discuss which variables might be more difficult to investigate (eg
Choose a variable to change
Decide how you will measure whether the change has made a
difference or not.
Once you have chosen your variable:
Decide what question you are going to investigate
Make a prediction
Give a reason for your prediction
Identify the variables that you are going to keep the same.
About your method:
How will you carry out a fair test?
How will you record results?
Who will be responsible for watering your plants?
How will you present your results?
Once pupils have planned their investigations they should spend the last
30 minutes of the lesson planting and setting up.
Refer to separate guidance sheets on setting up/conducting
investigations that vary:
Light (light and dark).
Plenary: What question is your group going to investigate?
What do you expect your results to be?
How will you tell if your prediction was correct?
Resources: Pictures of healthy/unhealthy plants; small pots; plant seeds; different
growing mediums; plant fertiliser; trays/boxes to hold pots; labels (eg to
record the watering regime for a particular set of plants).
Safety: When handling seeds, compost, fertiliser, etc:
Don’t put hands or anything you are handling in your mouth
Don’t inhale anything you are handling
Wash your hands when you have finished setting up.
Please see additional health & safety information included with the
separate guidance sheets on each investigation.
Ideas for further Make sure that your group takes at least three photos of your plants over
learning: the next two weeks. What changes can you see?