Year 2 science · Key Stage 1 · Plants

Year 2 plants: seeds, bulbs and what plants need to grow

In Year 2, children watch seeds and bulbs grow into mature plants and find out that plants need water, light and a suitable temperature to grow and stay healthy. They often grow plants in the classroom, record the changes over time and set up a simple comparison, such as one plant in the light and one in the dark.

How seeds and bulbs grow, explained

The national curriculum asks children to observe and describe how seeds and bulbs grow into mature plants. A seed contains a tiny young plant and a store of food. When the seed gets water and enough warmth, it begins to grow, which is called germinating. A root grows down first, then a shoot grows up. As the plant grows, it develops leaves and, later, flowers. After flowers come fruits or seed pods with new seeds inside, so the cycle begins again. A bulb, such as a daffodil or tulip, works in a similar way: it is a store of food underground, and with water and warmth it sends up a shoot and flower.

The key idea for parents to know is that seeds and bulbs need water and warmth to start growing, but most do not need light at that stage, because they have their own food store inside. Light matters later. Once the shoots appear and the plant starts to make its own food, it needs light. This is a common surprise, because many people assume seeds need sunshine from the start. A seed can germinate in a dark cupboard, but the seedling will soon become weak.

The second part is about what plants need to grow and stay healthy: water, light and a suitable temperature. Children find out by watching and testing. They might grow identical seedlings, with one watered and one not, or one in the light and one in a dark cupboard, and then compare them over a couple of weeks. In the dark, the seedling typically becomes pale, thin and droopy. The plant without water wilts. Children are asked to describe what they see, using words like healthy, wilted, pale, tall and thin, and to say what they think plants need.

Temperature matters too. Many seeds need some warmth to start to grow, which is why gardeners sow seeds in spring, and plants in a freezing place or in extreme heat may not survive. Children are not expected to know exact temperatures. Schools use the local environment through the year to observe how plants change, for example bulbs coming up in spring and vegetables growing in a school garden.

Because this is a topic of careful looking, measuring and comparing, it is a good place to practise working scientifically. Children measure with a ruler or with cubes, draw and label pictures at different stages, and record in a simple table or chart. There is no science test at this age.

Words your child will hear

Seed: A small part of a plant with a baby plant and some food inside it.
Bulb: An underground store of food from which a new plant grows, such as a daffodil bulb.
Germinate: To begin to grow from a seed.
Seedling: A very young plant that has just grown from a seed.
Shoot: The part of a young plant that grows up above the soil.
Mature plant: A fully grown plant.
Healthy: Growing well, with strong stems and green leaves.

What the National Curriculum says

In Year 2, pupils should be taught to:

Observe and describe how seeds and bulbs grow into mature plants
Find out and describe how plants need water, light and a suitable temperature to grow and stay healthy

Objectives from the National Curriculum in England, © Crown copyright, used under the Open Government Licence v3.0.

Try it: do plants need light to stay healthy?

A class has two bean plants, each about 5 cm tall, in pots of soil. They want to find out whether plants need light to stay healthy. How could they find out?

Predict. Children say what they think: “I think the plant in the dark will not grow as well.” The teacher writes the predictions on the board.
Plan the test. Put one pot on a bright windowsill and the other in a dark cupboard. They keep everything else the same: the same size of pot, the same soil, the same amount of water every two days, and a similar room temperature. Only the light is different.
Observe and measure. Every few days, they look closely, measure each plant with a ruler and draw both. They record the height and the colour in a table.
Compare after about two weeks. The plant on the windowsill is green and upright with strong leaves. The plant from the cupboard is pale yellow, thin and drooping. It may even have grown taller, as it stretches to find light, so the class talks about why taller does not always mean healthier.
Use the results to answer the question and check against the predictions. The cupboard plant is not healthy, so it needs light. The class may move the plant back to the window and see it recover, if it is not too late.

“Plants need light to stay healthy. The plant in the light stayed green and strong. The plant in the dark went pale and thin and drooped. We kept the water and the pots the same, so it was only the light that was different.”

Common mistakes and how to help

Thinking that seeds need light or sunshine to start growing

Plants and sunshine go together in a child’s mind, and we usually plant seeds in sunny places.

What helps: Seeds germinate in dark soil, and they need water and warmth. Plant a few seeds in a pot of soil and watch them appear; point out that the seed starts with its own food store and the plant needs light as it grows.

Believing more water is always better

Water is one of the things plants need, so children assume that a lot will help even more.

What helps: Talk about plants that have been left sitting in a puddle. Roots also need air, so too much water can be harmful. Water a little and often rather than flooding a pot.

Thinking that a plant eats the soil, or that soil is its food

Roots grow in soil and the plant gets bigger while the soil level stays about the same, so soil seems like the obvious food.

What helps: At this age, say that plants need water, light and a suitable temperature, and that seeds start with their own food. The full story of how plants make food is for later years.

Believing that a bulb is a kind of seed or a root

A bulb is planted in the soil, just as a seed is, and it has roots coming from the bottom.

What helps: Ask an adult to cut an onion in half, as an onion is a bulb, and look at the layers together. Explain that a bulb is a store of food. Roots grow from the bottom of the bulb and shoots from the top.

How to help at home

Grow cress or beans on the windowsill. Damp kitchen paper in a tray, or a bean in a clear jar with damp tissue, lets you watch the root and shoot appear. Take a photo or draw it every day for two weeks.
Plant a bulb in autumn. Daffodils and tulips can be planted in a pot of compost outdoors and left through the winter. Ask your child to predict when it will come up. Daffodil bulbs are poisonous and tulip bulbs can irritate skin, so wear gloves if you have them, wash hands after planting and never taste them.
Set up a light test. Plant two identical pots and put one on a bright windowsill and one in a cupboard. Water them equally. Ask your child to predict what will happen and why, and measure the plants once a week.
Measure growth. Use a ruler or a strip of paper to measure a plant each week, and keep the strips in a row to make a graph on the wall. It is a lovely way to see the pattern of growth.
Spot seeds in the kitchen. Look at an apple, a pepper, a tomato and a pea pod, with an adult doing any cutting. Ask what is inside each and what would grow from it. Remind your child that only food from the kitchen is for eating; garden seeds and bulbs are not.

Builds on

Year 1: Common plants and their parts

Leads on to

Year 3: Parts of plants and life cycles

Everything in Year 2 science

Updated 20 October 2026.