Nature and farming · How do plants live?

From seed to seedling: germination

Dried beans in the pantry sleep for years, yet sprout within days on damp cotton wool. Discover the water, warmth and oxygen that wake a seed, why lettuce seeds won't germinate in the heat, and in which seasons beans and lettuce are sown in Türkiye.

15 min
2 simulations
Mini quiz

Updated: 22 October 2026

Preview

The question

A jar of dried beans in the kitchen cupboard can sit there for months, even years, doing nothing at all. But put one of those beans on damp cotton wool and within three or four days its coat splits and a little white root pokes out. The bean in the jar wasn't dead, but it gave no sign of being alive either. What wakes a seed up? And why do some seeds wake up only in certain seasons, and not under just any conditions?

Try it yourself

No account needed: change the values and check your answer. Some simulations ask for a prediction before they start; it doesn't matter whether it's right or wrong.

Plant growth

Wake up a bean seed

Move the water and temperature sliders, and watch each factor's score and the limiting factor. There's no light in this model: a bean seed doesn't need light to germinate. When germination reaches its highest level, press Check.

Predict first

What do you think happens if you drop a bean seed to the bottom of a glass of water and wait?

It doesn’t matter whether you’re right; the simulation opens once you choose.

Plant growth

When does a lettuce seed wake up?

Move the water and temperature sliders. As you raise the temperature step by step, watch the temperature score. When germination reaches its highest level, press Check.

Predict first

What do you think happens to lettuce seeds sown in July in soil at 30 °C?

It doesn’t matter whether you’re right; the simulation opens once you choose.

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Frequently asked

5 questions

Does a seed feed on the soil around it?

No. In the first days of germination the seed lives on the food store in its cotyledons or endosperm; from outside it takes only water and oxygen. The fact that it can germinate on a wet paper towel, with no soil at all, proves this.

Will a seed germinate faster if I sink it in water?

No. The waking embryo respires and needs oxygen. A seed that is fully under water, or sown in soil as wet as mud, runs out of air and can rot. What it needs is a moist but airy place.

Do all seeds need light to germinate?

No; "they all do" and "none of them do" are both wrong generalisations. Beans germinate happily in the dark of the soil. Small seeds such as many lettuce varieties do need light, which tells them they are near the surface. That is why lettuce seed is covered only very thinly.

If lettuce seed sown in summer doesn't come up, is it dead?

Most likely not. The seed of many lettuce varieties stops germinating and waits when the soil goes above about 25–30 °C; this is called thermoinhibition. Once the soil cools down, the seed can wake up.

Can I eat the bean sprouts I germinated?

No. Raw or undercooked dried beans and borlotti beans contain a protein called phytohaemagglutinin, which causes nausea and vomiting. The experiment is for observation only; if you like, you can plant the sprouts in a pot and keep growing them.