I love sunflowers. I mean, who doesn’t? They are friendly flowers, and it is quite beautiful to watch them turning their yellow heads to follow the sun.
While not all plants can follow the sun quite as a sunflower does, most do grow towards the sun or towards the light.
I always wondered why this was, which is why I wanted to know why plants grow towards the light.
Plants are adapted to grow in a particular direction. The reasons plants grow either up or down is due to a need for water or a need for light (phototropism).
Plants grow towards light due to several reasons, and understanding which motivation your plants will have for their growth direction can help you plan better as a gardener to ensure your plants remain healthy and can enjoy a full greenery life for longer.
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Why Do Plants Grow Towards the Light?
By following the light or growing towards the light, plants can increase their light exposure. Another reason is that it helps them in their germination process. It also enables them to know which way is up towards oxygen and light and which way is down towards water and nutrients.
Reasons Plants Grow Towards Light
Germination by Growing Towards Light
In plants that reproduce with seeds, it is important for the plant’s growth that there is a clear indication of what is up and what is down when the seeds are sown in the ground.
I know that when I am busy propagating rhizomes, I need to be especially careful about what side of the rhizome I place up or down in the ground.
You see, the sunlight warms the ground, causing the leafy nodes to begin growing.
When you plant under the soil, sunlight is the determining factor to help your plants know which side is up.
This boils down to whether their roots will grow towards the soil where they belong or if the stems will form and grow in the wrong direction (and soon die).
Light helps seeds germinate and grow towards the light (or up), while their roots grow away from light (down) where they can collect water and minerals from the soil.
Maintain Healthy Processes
Plants will grow towards light since they need the solar energy of sunlight or light to help them process and make food that can be stored during photosynthesis. This is why my houseplants need to be turned every couple of weeks.
You see, if I don’t turn my plants, they will begin to grow unidirectionally.
They will grow towards the light, with the other side of the plant being left in the dark, which means it will soon sicken and begin to lose leaves on the “dark” side.
Avoid Competition for Resources
While you may not think it, plants can be highly competitive for resources.
If I plant a few orchids under the big tree in my yard, I can be sure that in a few months, the orchids will have begun growing away from the tree, towards the light.
For plants, light means life. A plant that has been left in the dark will soon sicken and die.
How Plants Grow Towards the Light
Plants have stems, and in these stems, there are billions of cells. When these cells begin to lengthen and reproduce, the plant will shift its position accordingly.
So, if I am honest, I forgot to turn my pothos plant for a season, and the next season, I was horrified that my lovely plant was green on one side with lush leaves, while on the other, it was gray and had lost most of its leaves.
To grow in a specific direction, the plant will have to lengthen specific cells in its stems. These plants have developed to grow away from the gravitational pull of the Earth or towards light.
As a result, these plants can literally grow around corners. By lengthening the cells on the side that is away from the sun, the plant will force its growth towards the light.
Frequently Asked Questions about Why Plants Grow Towards the Light
Why do plants grow towards light?
Plants need light, and they need to manage their growth so they will have enough light exposure. They accomplish this with a specific growth hormone known as auxin, which helps the cells on that side of the plant’s stems to lengthen and stretch, helping the cells on the other side to contract and pull the plant towards the light.
Why do plants grow taller in sunlight?
When plants receive loads of sunlight, it will result in them growing equally on all sides of their stems, which will improve their overall growth rate. Essentially, the auxin or growth hormone in their stem cells will react to the sunlight and grow. If there isn’t enough sunlight, the plants will grow less. Plants will naturally grow faster on the side that receives the most light, which will lead to the plant “growing” towards the light. This effect of lopsided growth is caused by the auxin that gets the most light, and this results in more growth. On the shadow side, the plant will grow less, and it will curve over more into shadow, and with time, you can end up with a plant that grows at an odd angle or even around a corner.
How can I make my plants taller?
Plants grow taller when their needs are all met. Be sure to provide sunlight, water, and nutrients as per your plant’s requirements. Rotate pot plants to ensure upwards growth and not sideways growth.
The Final Ray of Light
Plants thrive when they meet their watering and sunlight needs.
By growing towards the light, plants can gain height, compete better for resources, and ensure they create enough space for themselves to produce fruits and reproduce.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.