What Does a Seed Need to Grow? A Bean Experiment for Kindergarten to Grade 2

Planting a bean is a rite of passage in primary school. It’s easy to do and hard to forget. But with a little structure, the same activity can turn into a real experiment about what a seed needs to start growing.

The question

“What does a seed need to grow?” Children will say water, sun, soil, love. Take each idea seriously, then say, “Let’s find out.” That’s the move from guessing to testing.

What you need

Dried beans (garden bean seeds sprout most reliably; grocery-store lima or pinto beans work too)
Three zip-top bags
Paper towels
Water
Masking tape and a marker
A dark cupboard or a box with a lid

Set up three bags

Bag 1: damp paper towel, beans inside, on a sunny windowsill.
Bag 2: damp paper towel, beans inside, in a dark cupboard.
Bag 3: dry paper towel, beans inside, on the windowsill.

Put 4 or 5 beans in each bag so one stubborn seed doesn’t ruin the result. Label each bag. Keep the temperature similar for all three.

Before you start, ask children to predict which bags will sprout and why. Let them draw their prediction.

The picture journal

Look at the bags every day for 7 to 10 days. Children draw what they see, with the date. A simple chart helps: a column for each bag and a row for each day, with a tick for “sprouted.”

What usually happens

Bag 1 (wet, light): the seeds swell, split their coat, and a root pushes out first. A shoot follows and turns green.
Bag 2 (wet, dark): the seeds sprout too, often just as fast. The shoot may be pale and long and stretching, because the young plant is reaching for light.
Bag 3 (dry): nothing happens.

The surprising result for many children is bag 2. Seeds don’t need light to start growing. They have a built-in food supply, inside the seed, to get them going. Light matters later, once the little plant is up and has to make its own food. (A few kinds of seeds do need light to sprout, which is why it’s good to name the beans you used rather than say “all seeds.”)

Seeds also need a suitable temperature, and air for the new plant to breathe, which is why a seed buried too deep or soaked in a flooded pot may not do well.

What’s inside a seed?

Open a soaked bean gently (a grown-up can help with the seed coat). Inside you’ll see a tiny plant, the embryo, folded between two halves that hold stored food. Our lesson What’s inside a seed? lets children look at exactly that.

Make it a fair test

Remind children what has to stay the same: the same kind of seed, the same amount of water, the same bag, the same temperature. Only one thing changes between bags. That is the central idea of fair testing, at a level a six-year-old can grasp.

Questions kids ask

Why do the plants lean toward the window? Plants grow toward light. Our lesson Why do plants grow toward the window? lets children test it.

Do I need soil? Not to sprout. Soil provides nutrients later on.

Why didn’t one bean sprout? Some seeds are old or damaged. That’s why you plant several.

Keep going

The full activity is in our lesson What does a seed need to grow?, part of the Plants and Seeds unit. Older students can continue with How can a seed travel without legs? Sign up to get three lessons free.