SUNFLOWER LIFE CYCLE FOR CHILDREN AND ADULTS (WITH PICTURES) - BIOLOGY - 2025

The life cycle of the sunflower begins when the seed is planted in places with a warm climate where many hours of sun are received per year. Germination can be delayed from five to twelve days after being sown, provided the temperature and humidity conditions of the soil are optimal.

Once the seed germinates, it is in charge of taking root deeply in the earth. Only a stem leaves the outside of the seed, which is responsible for exceeding the surface of the earth. A single sunflower can develop roots up to 1.8 meters deep that support heights of up to three meters.

Scheme of the sunflower life cycle: it is born, dies and reproduces.

Sunflowers are quite particular plants, since they always try to orient themselves facing the sun and throughout their lives they develop strong and deep roots that allow them to reach significant heights compared to other flowers. Once they reach maturity, they are essential for the bee pollination process.

The life cycle of the sunflower is divided into six stages that go from the sowing of the seed to the growth, death and renewal of the cycle of each flower, being a relatively fast cycle.

Sunflowers usually grow in the summer, when the weather is warm. They are called this way because the flower will always try to orient itself towards the star as it moves (Sieverson, 2017).

Sunflower life cycle processes

1- Sowing the seed

The life cycle of sunflowers begins when they are small seeds. Normally, these seeds are covered by a thick layer that can be black with cream-colored stripes or completely black.

The sunflower seed is protected by this layer when the weather is hostile. However, once the conditions are conducive for the seed to germinate and the temperature rises, this layer falls off, allowing the sunflower roots to sprout.

Sunflower seed sowing occurs during the spring, when the temperature is warm. This is because sunflowers need a lot of sunlight throughout their life in order to grow.

2- Seed germination

Planted sunflower seeds begin to germinate or sprout after five days, although some seeds may take a little longer, taking up to twelve days to sprout.

The protective layer of the seed softens during this process due to the humidity of the soil and, thanks to the increase in temperature, this layer falls off, allowing the roots of the seed to sprout.

The first root that sprouts from the seed is deeply anchored in the ground and a single stem is responsible for exceeding the level of the ground. Once the stem grows and exceeds the level of the ground, it is called a seedling (Yastremsky, 2014).

3- Seedling growth

The seedling continues to grow as the temperature increases. In this same way, the root of the sunflower also grows deeply, anchoring itself to the ground. This root can reach up to 1.8 meters deep, allowing the sunflower to grow tall and heavy.

As the seedling develops, it sends a message to the root so that it also grows. In this way, the root acts as if it were the anchor of a ship, which in turn has the ability to obtain water and nutrients from the earth.

This root will always be formed by a preponderant axis (pivot root) and several smaller roots located radially along the main root (Jones & Brundle, 2015).

The stem of the seedling will continue to grow and develop more shovel-shaped leaves as it gets taller. This stem is initially hollow, smooth and rounded and will give way to the growth of a flower bud after thirty days. Once the bud begins to grow, the stem becomes strong, angular, and thick.

While the flower bud is young, it will follow the sun from east to west as it moves across the horizon on sunny days. This way, the sunflower button will point east in the morning and west in the afternoon. This phenomenon ceases to occur once the sunflower reaches maturity.

The stem height of a mature sunflower can range from about 2.4 to 3.6 meters. Some researchers at Purdue University have noted that the best conditions to ensure the growth of a sunflower occur when the temperature reaches 25 ° C (Burghardt, 2008).

4- Flowering

It takes about three weeks for the sunflower bud to become visible at the end of the plant's stem. This button begins to grow until it finally opens, taking the shape of a disk with yellow petals.

Over the course of the week after blooming, the flower's yellow petals roll back over the edges of the button head.

After a week the sunflower drops its petals and the secondary shoots located in the lower part of the stem can bloom as smaller buttons (Thomson, 2010).

5- Wilting

After a season of growth and life, the sunflower petals begin to fall off and the flower begins a wilting process. Eventually, the sunflower bud will shrink and release seeds so that they fall into the deeper parts of the soil surface.

Once the sunflower finishes its blooming process, the dots in the central part of the bud swell into seeds, taking approximately thirty days to mature. Once they mature, each seed dries up and gradually falls to the ground and is taken up by small rodents, birds or humans to be consumed as food.

As the seeds mature, the rest of the sunflower plant begins to shrink, taking on a yellowish color. This phenomenon happens because all the energy of the plant is focused on the growth of the new seeds (Royston, 1998).

6- Regrowth

Once the sunflower seeds settle in a suitable place, the life cycle of the sunflower begins again.

When all the seeds ripen and fall naturally, the sunflower plant stops growing and only dies at nightfall, when the temperature drops (Phelps, 2015).

References

1. Burghardt, J. (2008). Garden Guides. Retrieved from The Life Cycle of a Sunflower Plant: gardenguides.com.
2. Jones, G., & Brundle, H. (2015). Life Cycle of a Sunflower. Book Life.
3. Phelps, B. (2015). The Life Cycle of a Sunflower. PowerKids Press.
4. Royston, A. (1998). Life Cycle of a Sunflower. Heinemann Library.
5. Sieverson, D. (2017). com. Retrieved from Sunflower Lesson for Kids: Facts & Life Cycle: study.com.
6. Thomson, R. (2010). A Sunflower's Life Cycle. New York: The Rosen Publishing Group.
7. Yastremsky, M. (2014, July 22). The Petal Talk. Retrieved from THE LIFE CYCLE OF A SUNFLOWER: 1800flowers.com.