How does a seed become a plant? It starts as a baby plant with a coat around it. The coat protects the baby plant from injury and from drying out. Some coats are thin and soft, like a bean's, and some are very hard, like a coconut's. A hard coat may need to be scratched before the seed will sprout.

A seed can wait, doing nothing, until the conditions are right. It needs water, and a dry seed soaks it up and swells. It needs air with oxygen in it, and soil soaked with water can leave it with too little oxygen. It needs to be warm enough, too. Most vegetable seeds sprout best in soil that is about 65 to 75 degrees Fahrenheit. Apple seeds will not sprout unless they have a cold spell first.

When a seed sprouts, its first root comes out of the seed coat first. Next, a shoot grows up with the leaves and the stem. Roots hold a plant in the ground and take in water. Most plants have roots, stems and leaves.

Plants make their own food. This is called photosynthesis, and it uses sunlight, water and carbon dioxide. A stem holds the leaves up so they can reach the sunlight. Plants look green because of chlorophyll, which takes in blue and red light. Photosynthesis makes sugar for the plant and gives off oxygen, which people and animals breathe.

Leaves take in carbon dioxide and give off oxygen through tiny openings called stomata, and water vapor leaves through them too. Plants take up liquid water from the soil and let water vapor go from their leaves into the air. This is called transpiration.

Flowers are how plants make seeds. Pollination is moving pollen from the anther of a flower to the stigma. Many plants need bees, butterflies, birds, bats and other animals to carry pollen from flower to flower. After pollination, the ovule inside a flower becomes the seed and the ovary becomes the fruit.

Then the seeds must travel. Some have wings or fluff, so the wind can carry them away, like maple and dandelion seeds. Burrs have little hooks that stick to animal fur, so animals carry the seeds away. A coconut is a seed that floats, and it can drift across the ocean and grow in a new place.

Some seeds grow into giants. Coast redwoods are the tallest trees on Earth, about 380 feet tall. As of November 2026, the tallest one known is 379 feet. A giant sequoia starts as a seed about the size of a grain of oatmeal, and it can live for more than three thousand years.

Words to know

• stomata: tiny leaf holes
• chlorophyll: green plant stuff
• pollination: moving pollen
• transpiration: plant water loss