ELI5: What are auxins?

Imagine you have a group of friends, and one friend is really good at telling everyone where to go and what to do to have fun. Auxins are like that friend for plants!

Think about your plants at home. They grow towards the sunlight, right? That's because of auxins.

• What auxins are: They are special hormones (tiny chemical messengers) that plants make.

• What auxins do: They tell the plant's cells to grow bigger and longer, especially on the side away from the sun.

Auxins also help plants grow taller, make roots, and even help fruit develop!

• If you ever used rooting powder to grow new plants from cuttings, that powder contains auxins! It encourages the cutting to grow roots.
• Auxins prevent leaves from falling off too early.
• Auxins are responsible for the pointed shape of Christmas Trees. The top bud produces more auxins, preventing lower side branches from growing as much.