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Using tea leaves to enhance plant growthFeatured science projectScience project video


The materials required for this science fair project:
- 10 potted rose plants of almost the same height
- Used tea leaves
- A ruler
- Gardening utensils
- Water
- A black marker pen


1. For this science fair project, the independent variable whether the soil has been mixed with tea leaves or not. The dependent variable is the growth rate of the rose plants. This is determined by measuring the height of the rose plants every week. The constants (control variables) are the size of the pot, the size of the plant, the type of rose plant, the amount of water and the amount of sunlight.

2. The 10 rose plants are separated into 2 groups of 5 pots each. The average height of the plants is obtained by totaling the height of the plants in each group and dividing that by 5. The average height calculated is recorded in the table below.

3. The rose plants in one of the groups are removed from their pots. Their soil is mixed with the used tea leaves. The mixing ratio should be 1 part tea leaves to 2 parts of soil. The rose plants are then planted back into the pots. The word “tea” is written on the 5 pots containing the tea leaves, to help differentiate them from the other group.

4. The 10 pots are placed in a location where they are able to receive the same amount of sunlight. They are watered once a day with the same amount of water.

5. The height of the plants is measured once every week for the next 4 weeks. The average height for each group of rose plants is obtained by totaling the height and dividing by 5. The calculated average is recorded in the table below.

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Complexity level:
Project cost ($):
Time required:
1 day to prepare, 28 days for science fair project
Material availability:
Easily found at a plant nursery
Safety concerns:

Basic safety requirements