Science fair projects with plants and seeds

What to expect

Plants make some of the best science fair projects, because they really respond to what you change. Change the water, the light or the warmth, and measure what the plant does with a ruler, day by day. They also give a judge something they love to see: a logbook with a dated line for every day, which shows the work really happened over time. The catch is time. Most of these take a week or more of growing, so start early, and check the days on each one before you pick.

The only living things on Peabody's science fair are plants. The beans come from a grocery bag, the grass from a bag of seed, and the celery, potatoes and green onions from the kitchen. Soil is fine, but wash your hands after it, and keep the dried beans away from little brothers and sisters, because they're small enough to swallow. If a seed doesn't come up, that's a result too: write it in the logbook, count it in your table, and say so in the conclusion. Some fairs keep all living things off the display table, so bring photos and the logbook instead.

Counted from the projects on this page: 1 about water, ice and mixing, 18 about growing and weather; 1 using kitchen things, 18 using the outdoors and some seeds. 7 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. 4 have a step a grown-up does, marked on the page.