How do plants make new plants without seeds?

1. Most plants you know grow from seeds. But many plants have a second way to make new plants: they grow one from a piece of themselves.
2. A strawberry plant sends out a long stem called a runner. A baby plant forms at its tip. Where it touches the soil it grows roots, fed by its parent until it can live alone.
3. A tulip bulb is a packed lunch: thick layers full of stored food around a tiny shoot. After the flower fades, the leaves feed new baby bulbs that grow at the side.
4. Cut a basil stem just below the bumps where leaves grow, and stand it in water. In a week or two, roots grow from those bumps. Plant it, and it is a whole new basil.
5. Each new plant grew from a piece of one parent, so it is a copy. It will have the same leaves, the same flowers and the same tasting fruit. A copy like this is called a clone.
6. Gardeners and farmers use these tricks to make many copies of their best plants, fast. Potatoes, bananas and most apples are grown this way.

Tap each part to see how it helps make a new plant.

• Runner. The runner is a long stem that grows away from the parent. It works like a drinking straw, carrying food and water to the baby plant at its tip.
• Baby plant. The baby plant has tiny leaves and the start of roots. When it touches damp soil, the roots grow down, and soon it can feed itself.
• Bulb. Cut a bulb open and you see layers, like an onion. They are thick, special leaves full of stored food. In the middle waits a tiny shoot, ready to grow.
• Baby bulb. A baby bulb grows from the side of the parent bulb. The plant's leaves make food to fill it. Next year it can grow a flower of its own.
• Leaf joint. The bump where leaves join the stem is called a node. It holds tiny buds that can turn into new shoots or new roots, so a cutting needs at least one.
• New roots. Roots do not usually grow from stems. But a cut stem can switch on new roots at a node. Once it has roots, the cutting can take up water and grow.

Tap to pin down the runner, plant the bulb and put the cutting in water. Watch the weeks pass. Which new plant is ready first?

Experiment: Which new plant will be ready first?

1. Tap the runner tip, the bulb and the cut stem to start all three.
2. Watch the week counters above each one.
3. Note the week when each new plant is ready.

What we found: The cutting is ready first, in about four weeks. The runner's baby plant takes about six. The baby bulbs take a whole growing season, because the tulip must flower first and then fill them with food.

Turn on JavaScript to try it yourself.

The garden needs a new strawberry, a new tulip and a new basil. Choose the right way to copy each plant, then press Grow.

When you think of a new plant, you probably think of a seed. But plants have another way. Many of them can grow a whole new plant from a piece of themselves. No flower and no seed are needed.

A strawberry plant sends out runners: long, thin stems that creep over the ground. A baby plant grows at the tip, puts down roots and soon lives on its own. A tulip grows from a bulb, a store of food under the ground, and baby bulbs form at its side. And a cut piece of stem from plants such as basil or mint can grow new roots in water.

How can a piece of stem do that? The secret is in the little bumps where leaves join the stem. Each bump, called a node, has tiny buds that can grow into a new shoot or new roots. That is why a cutting needs a node, and why the baby plants on a runner form at its nodes.

A plant made this way is a copy of its parent, called a clone. That is handy: a gardener can copy the strawberry with the sweetest fruit again and again. But there is a catch. If a sickness can hurt one of the copies, it can hurt them all. Seeds mix things up, so some seedlings may cope better. Our copy-machine comparison breaks down here: a paper copy stays the same forever, but a plant clone is alive and still grows differently in sun or shade.

Key words

Clone

A living thing that is an exact copy of its one parent.

Runner

A long stem that grows along the ground and forms baby plants. Its scientific name is a stolon.

Bulb

An underground store of food made of thick leaves around a tiny shoot.

Cutting

A piece cut from a plant that can grow roots and become a new plant.

Node

The joint on a stem where a leaf grows. It holds buds that can make new shoots and roots.

Vegetative reproduction

Making new plants from the stem, root or leaf of one parent instead of from seeds.

Check your thinking

1. How does a strawberry plant copy itself?

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   It sends out a runner with a baby plant on it. The runner carries a baby plant away from the parent, and it roots where it touches the soil.

2. Why is a plant grown from a cutting just like its parent?

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   It grew from a piece of that one parent. A cutting is part of the parent plant, so the new plant is a copy of it: a clone.

3. You put a piece of stem with no leaf joint in water. What will happen?

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   No roots grow, because roots start at a leaf joint. The buds that can make roots and shoots sit at the leaf joints, so a cutting needs one.

4. What is one problem with a field where every plant is a copy of the same plant?

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   One sickness could hurt them all. Copies share the same weak points, so a sickness that can hurt one can hurt every one.

5. What are the layers inside a bulb for?

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   Storing food for the plant. The layers are thick leaves packed with food, ready for the shoot to use.