Would caffeine affect the germination of a seed?


Problem- How does caffeine effect the growth in plants?

Hypothesis- If 3 mung bean plants are being watered by coffee, caffeine, and water then the coffee would make the mung bean plant grow the fastest because it has natural organic substances with natural caffeine that would stimulate the plant to grow the fastest.


1. For this project, the independent variable is the solution used to water the plants – water, caffeine solution and a coffee mixture. The dependent variable is the growth of the mung bean plants. This is determined by measuring the height of the plants every day using a ruler. The constants (control variables) are the size of the pot, the concentration of caffeine and coffee, the amount of sunlight, the temperature of the environment (which will remain at room temperature) and the amount of water added daily.

2. Fill the 3 cups with equal amounts of soil. Plant ten mung beans in each pot and allow them to germinate.
3. For the first 5 days, water the 3 cups with tap water only. Allow the seeds to germinate for the first 5 days.

4. After 5 days, measure the height of the 10 plants in each cup. Add up the individual heights and divide by 10 to obtain the average height. Record the average heights in a table, as shown below.

5. Prepare the caffeine solution by dissolving 10g of caffeine tablets in 100ml of water in a beaker. Label the beaker ‘caffeine’. Similarly, add 5g of coffee to 100ml of water in another beaker and label it ‘coffee’.

6. Label the 3 pots water, caffeine or coffee. Over the next 10 days, water the pots once a day with 100ml water, caffeine solution or coffee mixture, according to the labels on the pots.

7. Measure and calculate the average height of the mung bean plants every day for the next 10 days. Record all calculations.


After 10 days the mung bean plant that was watered was 107mm tall, the plant that was watered with caffeine was 71mm tall, and the plan that was watered with coffee was 125mm tall.


  • One packet of mung beans
  • 3 solo cups or Styrofoam cups (Recommended)
  • Soil (enough for each cup)
  • Tap Water
  • Caffeine tablets
  • Unbrewed Coffee grinds
  • 3 Beakers
  • Ruler
  • Black marker


The hypothesis that mung beans watered using a coffee mixture will grow the fastest has been proven to be true.

The effect of caffeine on plant growth is still a subject under study. Using grounded coffee in garden lawns is a common practice to make plants grow faster. However, coffee also contains other ingredients like potassium and phosphorous, which are known to enhance plant growth. Experiments on plant growth using only caffeine have resulted in the plant leaves becoming wrinkled, turning brownish and exhibiting retarded growth.