The Experiment

Hypothesis:

It is hypothesized that considering that zinnia's prefer more acidic soil types, the neutral and acidic plants will do the best. The basic plants will probably not do as well and may even die.


Materials:

Zinnia seeds (25)
3 lemons
water
30 mL soap
pH 9 buffer
soil
source of light
beakers


Procedure:

1. Plant seeds in 3 separate, equal sized pots. Use only dirt in each pot. Make sure to put and equal amount of seeds in each pot.

2. Once a week, water each plant 10 mL with it's respective water type. The mixtures are as follows:
Acidic - 20mL lemon juice and 20mL water mixed together
Basic - 10mL soap and 30 mL water mixed together
Neutral - 40mL water
The mixtures can be adjusted to make more liquid, however the ratio must stay the same.

3. Each week record the growth of each plant in a journal.


Discussion: 

If the experiment were to be done again, a pH 9 buffer would be used in place of the soap. Soap would not be used as it is thought to have a chemical in it responsible for directly killing the plants. Another good amendment to the experiment would be to make sure there are extra seeds in case a replanting must occur.

Conclusion:

It was found that the hypothesis was correct; the Zahara Starlight Rose Zinnia's prefer neutral to acidic pH levels in the soil as opposed to basic levels. It was also found that the soap we used to create the basic pH had a chemical in it that killed both the Zinnias as wells as the kohlrabi. The kohlrabi did not die due to the pH 9 buffer, so it would be ideal to test that on the Zinnias as well.