I think that plants will grow taller together because trees communicate with each other so it makes sense for the plants to grow taller when they are near each other.

Scientific research from ScienceNews, article Plants Packed close enough to touch are more resilient to stress. This article proves that plants that are touching can reduce more stress from bad weather, too much water or  too little water. They think the reason why is because like people, plants like to be in a community, the community are very supportive to each other.

Even in a basic forest, when you look underground the mushrooms are helping the trees send and receive nutrients from other trees.There is no such thing as a lonely plant in the wild. Every tree and every plant is helping another plant. The ecosystem of plants in the forest are all giving to every one.

Allelopathy is when direct or indirect, good or bad effect on a plant by releasing chemicals into the air or soil. A plant could send some chemicals to another plant by air or in the soil. By sending these chemicals into the air can have a positive or negative effect on the receiver plant.

My question is “ Will Plants Grow Better Together or Alone?”

My independent variable is that the plants will be together or alone.

My dependent variable is the plants height.

My controlled variables are how much water they get, the amount of sunlight and the type of soil.

Here are the steps to do my experiment.

Materiels 9 pots all of the same size 9 sunflower seeds 1 ruler Pieces of cardboard A metal tin pan

Procedure

1 First line up the cups so that you have 6 of the cups in pairs of two 2 Put pieces of cardboard between the pairs so the can’t see each other. 3 Put pieces of cardboard of cardboard between the three other pots, so they can’t see the other plants. 4 Pour soil into the each pot so there is only 1 centimetre left until the pot is dull. I used Miracle-gro indoor potting mix. 5 Put the metal pan under the plants to catch any water or loose dirt. 6 Once they start growing measure once a week.

Make sure to water every other day 2 centimeters.

|Pair 1

So in week one Solo 3 were the tallest. As you can see Pair 3 did not sprout at all. At the end of a month Solo 2 was the tallest therefore proving my hypothesis wrong.

| | |

So based on my chart it looks like pair 1 has only a centimetre taller then there partner while pair 2 has a 2-3 centimetres difference. During week four I noticed that one of the plants in pair 1 were leaning towards the other plant, while the other plant leaded away. I think that maybe they were looking for more sun. In the end my chart shows that Solo 2 grew 18cm taller then any other plant.

Based on my notes it looks like my hypothesis was proven wrong. My data proves that the Solo 2 grew 18 cm in a month, taller than any other plant. My hypothesis was that the plants in pairs would grow taller together. Each of the plants had the same amount of water and sunlight. But still Solo 2 was the tallest out of the nine plants.

You could use my results to help you when you’re gardening. This knowledge is helpful to know so you don’t plant the plants close together. You would know that even if you plant them close together each other they would still grow but if you plant them a bit more far away then they would grow better.

I think that maybe next time I should put the seeds into one long pot so they can communicate better instead of with their leaves which does work for them. I feel lie next time I would put the plants in separate pans because I used one pan for nine pots an I think because there were pieces of cardboard the pair in the middle Pair 3 didn’t get as much sunlight as the other plants. Maybe next time I would do the experiment in the summer because plant don’t generally grow in the winter and there isn’t as much sunlight.

My source

Richard Kemen (January 14 2026). Plants packed close enough to touch are more resistant to stress. ScienceNews. https://www.sciencenews.org/article/plants-touching-stress-resilient

Dave Hansford. The wood wide web. New Zealand Geographic https://www.nzgeo.com/stories/the-wood-wide-web/

Erica McRAE. ( July 10 2024). Allelopathy in Plants: Mechanisms, Impacts and Practical Application. Plant and Heal https://plantandheal.com/blogs/plant-something-heal-something/allelopathy-in-plants-mechanisms-impacts-and-practical-applications?srsltid=AfmBOop39MfEg7iem_-rlBKJV6RKRibgQeF8C1O_kvSZCt5UfrqEb2hh

Mst. Motmainn et al. (2023). Allelopathic Potential of Tropical Plants. MDPI. https://www.mdpi.com/2073-4395/13/8/2063

My parents helped me with this by driving me to find a place that can print in colour and paying for all of my materials. My science fair teacher who also helpers me with my project.