Plants are patient, honest experimental subjects: give two groups different light, water or soil and they will show you the answer — as long as you wait long enough and measure carefully. These projects run from one-week seed germination tests to multi-week growth comparisons.
36 published projects in this collection
Plan backwards from your deadline: germination experiments need about a week, growth comparisons three or more. Use several identical pots per condition — one plant can die for reasons that have nothing to do with your variable — and measure height or leaf count on a fixed schedule.
Photograph your setup on day one and every measurement day. A simple photo log plus a dated data table is the difference between 'my plants grew' and evidence a judge can trust.
A materials list with costs, numbered steps, safety guidance, the variables to change and control, and a data table you can fill in — plus community results from other builders once people start sharing theirs.
By subject
By school level
By difficulty
Preparing for a fair? Read the science fair guide or record your data in the lab.
They are drawn from the whole library by topic, across every subject and school level, so the collection mixes quick afternoon tests with full science fair entries. Each project page states its subject, level and difficulty.
A research question and hypothesis, the independent and dependent variables, the variables to hold constant, a full materials list with costs, numbered steps, safety guidance and a data table you can fill in as you test.
It varies, so every project page states a cost estimate and a realistic time estimate up front. You can rule a project in or out before buying anything.
Some do. Every project lists its hazards and whether adult supervision is required in an at-a-glance panel on its page, so you can check suitability before you start.