Science fair projects with plants, sun and weather
These science fair projects use the outdoors, a windowsill and a few seeds: sun, shade, wind, water and growing things. 29 projects fit. Start with these 3.
- When is my shadow longest: morning, lunch or afternoon?kindergarten · 3 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Where does grass come up first: a sunny window, a shady room or a dark cupboard?kindergarten · 10 days of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- How does a shadow change through the day?1st–4th grade · 1 day of testing · free🌦️ Growing and weather · 🌱 Outside and plants
What to expect
Plant and weather projects take longer, because the sun and the seeds set the pace. That's what makes them good: a logbook with a line every day shows a judge the work really happened. They need a few days of planning ahead, so check the countdown before you pick one.
The only living things here are plants. No animals and nothing grown on purpose from germs or spores, because almost every school rule set leaves those to older students with forms and a teacher's sign-off. Wash your hands after the soil, and never look straight at the sun.
Counted from the projects on this page: 29 about growing and weather; 29 using the outdoors and some seeds. 15 are free with what most houses have, and the rest cost about $3 or about $2 or about $1. Testing takes from 1 to 21 days. 5 have a step a grown-up does, marked on the page.
All 29
- When is my shadow longest: morning, lunch or afternoon?kindergarten · 3 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Where does grass come up first: a sunny window, a shady room or a dark cupboard?kindergarten · 10 days of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- How does a shadow change through the day?1st–4th grade · 1 day of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Which warms up most in the sun: soil, sand or water?1st–4th grade · 1 day of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Does a pinecone close when it gets wet?1st–5th grade · 2 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Do green onions regrow best in water or soil?1st–5th grade · 7 days of testing · about $2🌦️ Growing and weather · 🌱 Outside and plants
- Do plants bend toward the window?1st–5th grade · 12 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Where does a puddle dry fastest: sun, shade or wind?2nd–6th grade · 2 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Where does the most rain land: the open yard, under a tree or by the house?2nd–8th grade · 7 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Do soaked beans sprout faster?2nd–6th grade · 7 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- How much water do bean seeds need to sprout?2nd–6th grade · 10 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Does a bean grow taller in the dark?2nd–6th grade · 10 days of testing · about $2🌦️ Growing and weather · 🌱 Outside and plants
- Do beans grow best in soil, sand or cotton?2nd–6th grade · 14 days of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- Do potatoes sprout faster in the light or dark?2nd–6th grade · 14 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Which soil lets water through fastest: sand, potting soil or garden soil?3rd–8th grade · 1 day of testing · about $1🌦️ Growing and weather · 🌱 Outside and plants
- Does a cover keep water in the sun warmer?3rd–7th grade · 1 day of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- Which colour of paper warms up most in the sun?3rd–8th grade · 1 day of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- Do seeds sprout faster somewhere warm?3rd–7th grade · 7 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Do bigger seeds sprout faster?3rd–7th grade · 7 days of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- Do roots grow down even if you turn the seed?3rd–7th grade · 7 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Does planting a seed deeper make it slower to come up?3rd–8th grade · 14 days of testing · about $1🌦️ Growing and weather · 🌱 Outside and plants
- Does a steeper hill wash away more soil?4th–8th grade · 1 day of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Do leaves give off more water in sun or shade?4th–8th grade · 1 day of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Where is it windiest around your home?4th–8th grade · 3 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
- Does grass grow best under red, blue or green light?4th–8th grade · 14 days of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- Does salty or sugary water change a bean plant?4th–8th grade · 14 days of testing · about $2🌦️ Growing and weather · 🌱 Outside and plants
- Do crowded seeds grow shorter?4th–8th grade · 14 days of testing · about $2🌦️ Growing and weather · 🌱 Outside and plants
- Do grass roots stop soil washing away?4th–8th grade · 14 days of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
- Which kitchen scrap helps a plant grow most?4th–8th grade · 21 days of testing · about $3🌦️ Growing and weather · 🌱 Outside and plants
Find a project
By grade
- Kindergarten
- 1st grade
- 2nd grade
- 3rd grade
- 4th grade
- 5th grade
- 6th grade
- 7th grade
- 8th grade
- Middle school
- High school
By time and by what you have
- 🗓️ This weekend
- 📅 About a week
- 📆 Two weeks or more
- 🧂 Kitchen things
- ✂️ Paper, tape and toys
- 🌱 Outside and plants
- ⭐ Easy ones
- 🏠 What's at home?
About a topic
- 🍎 Food
- 🍬 Candy and sugar
- 💧 Water
- 🌱 Plants and seeds
- 🎵 Sound and music
- ⚽ Sports
- ✈️ Paper airplanes
- 🌦️ Weather
- 🟢 Slime
- 🧲 Magnets
- 🐾 Animals
Sheets to print
Get ready for the fair
👨👩👧 For grown-ups and teachers: how much to help, the safety rules, and running a school fair. Science fair v0.16.1 · Checked .