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What is the Effect of Hydroponics on the Root Growth of Peperomia Shoots?

Researched by Carissa H.



The purpose of this experiment was to determine in which condition plant shoots grow roots best: the conditions were in chemical solution, tap water, and soil.

I became interested in this idea when I saw that some plants can grow hydroponically and others cannot.

The information gained from this experiment can give scientists ideas on future experiments.  Scientist have not proven whether or not hydroponic gardening could substitute for normal gardening. This information gained can also help gardeners possibly grow stronger healthier plants.


My hypothesis is that when starting leaves hydroponically that roots will grow faster than the leaves in soil.

I base my hypothesis on the fact that when leaves fall to the ground, in dirt or mud, they do not grow roots.  I also base my hypothesis on what Raymond Bridwell wrote in his book, ìThe Magic of Hydroponic Gardening.î  The book says this process is, (In this quotation he is writing about growing plants through hydroponic gardening.) ìÖmodern, automated hydroponic gardening.î


The constants in this study were:
 -the location of each container
 -the size of each container (165 ml)
 -the type of plant ( Peperomia  )
 -amount of water each plant received every other day (15 ml)
 -each plants growing time (2 weeks)
 -the type of each container (Plastic cups)
 -the size of each plant shoot
 -temperature where plants are growing

The manipulated variable was to find out in which condition plant shoots grow roots best. There were three groups with three plants in each group. Each group received a different substance (water, chemical solution, and soil).

The responding variable was the growth of each plant roots after two weeks. I checked to see in what condition the plants grew best.

To measure the responding variable I measured all groups in millimeters after two weeks.



Quantity Item Description


Plastic 165 ml clear cups


Plant shoots 10 cm long


Bottle of Shultz Plant Food Plus


Bag of potting soil (House plant)


Bag of 165 ml cups (at least 9)


Designated room for growing


 Peperomia plants (in 20 cm pots)


Portable tray



  1. Gather materials.
  2. Take the nine plastic 165 milliliter cups out of the package and place them in front of you.
  3. Take three cups, and with a black pen, label them Group #1 on the bottom of the cup.
  4. Label the first three cups in Group #1 like this:
  5. The first cup a
  6. The second cup b
  7. The third cup c
  8. Place cups on the portable table in a row.
  9. Take three more cups, and with a black pen, label them Group #2 on the bottom of the cup.
  10. Then label these like in step four.
  11. Place cups on the portable table in a row.
  12. Take the last three cups, and on the bottom of the cup, label these cups Group #3.
  13. Label these cups like in step four.
  14. Place on the portable tray in a row.
  15. Fill Group #1 with 50 milliliters of cool tap water.
  16. Fill Group #2 with 37.5 millimeters of potting soil and 15 milliliters of cool tap water.
  17. Make chemical growth solution. Use 10 drops of Shultz Plant Food Plus and one liter of cool tap water .
  18. Fill Group #3 with 50 milliliters of the chemical growth solution.
  19. Cut 9 plant shoots making sure that each is 10 centimeters long.
  20. Place one of the shoots in the center of each cup, so that the bottom tip of the plant just touched the bottom of the cup.
  21. In Group #2 make it so that the potting soil holds the plant straight.
  22. Move the tray into the designated room.
  23. Place the tray in front of the window in the designated room.
  24. Water each plant that is in Group #2 every other day starting on the second day of your experiment.  When watering use 15 milliliters of cool tap water.
  25. Measure roots at the end of 2 weeks. Record length of root from the base of the leaf to the tip of the root when gently pulled straight.
  26. Repeat steps 2-23 for a second trial.



The original purpose of this experiment was to determine whether or not hydroponic gardening works better than soil gardening.  To also see in which condition roots grow best on 10 cm plant shoots.

The results of the experiment were that the best growing plants were the plants growing in the hydroponic groups.  The group with the smallest growth were the soil groups.


My hypothesis was that the plants growing hydroponically would grow better than the plants that were growing in the soil groups.

The results indicate that my hypothesis should be accepted because I had said that the hydroponic groups would grow better than the soil groups.

Because of this experiment, I wonder what type of rule there might be according to the type of plants that will grow hydroponically.

If I were to conduct this experiment again I would try another plant and also more tests in each group.


    Do you know that hydroponic gardening has been around for nearly 200 years? It was first developed in the 1800ís.  So what is the hydroponic gardening method? It is the process in growing plants in substances other than soil.  Even though it has been around for so long, a lot of people do not even know what hydroponic gardening is.  Hydroponic gardening is probably a better, faster way to grow plants than growing plants in soil.
    Hydroponic gardening is the process in growing plants without using soil. This method has been around for almost 200 years and scientists still do not know if it is a better way to grow plants or not. It works with three main methods water culture, chemical culture, and gravel culture. All three of these methods provide essential nutrients to all plants.  The growing medium, or the condition that the plants are growing in, can be anything that provides the essential elements that plants need to grow.  When growing plants in the hydroponic gardening method people still have to use the same amount of light and water.
Hydroponic gardening works, but soil does too.  The difference between hydroponic gardening and growing plants in soil is that hydroponic gardening is not as available. This is because most people can use soil in their yard why would they want to buy chemicals?  Maybe because hydroponic gardening works better.  People still use soil because it is available and they do not know too much about hydroponic gardening.  When you use soil by planting a plant you are enriching your soil.  This also breaks up the rock to make it easier to grow plants.  They also leave nutrients behind after they decay.  Soil can work probably just as well as hydroponic gardening.
    There are three different types of cultures in the hydroponic gardening method. The three methods are; the gravel culture, the water culture, and the chemical culture.  In the gravel culture people use gravel, water and sometimes chemical.  The gravel culture supports the plant so that the plant is suspended above water.  In the water culture people often use plain water.  This method is helpful because water supplies some of the essential elements that plants need to grow.  In the water culture, however, the plant is not supported.  In the chemical culture people use a variety of chemicals.  This method is helpful because this way you can test to see which chemicals work best in hydroponic gardening.  Although in this method again the plant is not supported.
    Water can not affect plant growth can it?  Yes it can and it is one of the main culture types of hydroponic gardening. Water contains essential nutrients that can help plants grow.  Water is made of 2 hydrogen and 1 oxygen molecule. The weight of water is mostly the oxygen that is 88.8% of the weight while hydrogen is 11.2% of the weight.  Plants can grow in water as long as the part where a leaf grows is under water because that is where roots will grow best.  The growth of roots is influenced by where the water source is.  Water culture is when you place a plant in water and expect it to grow.  The water culture is one of the main types of the hydroponic gardening method.
All plants have a certain climate that they grow best.  The best climate for the plant Peperomia is medium light and fairly dry soil.  Many plants can grow roots on a cutting.  Some examples might be Pothas, Grape Ivy, Wandering Jew, and Peperomia.  In order for plants to grow hydroponically, a leaf must have been cut off of the original shoot. Where leafs were or where leafs were trying to grow is the part that must be under water because that is where roots grow.  The roots on plants always grow toward gravity.  All plants need water but some do not need as much as other plants.  Even when growing hydroponically the plants still need the same amount of water.
    The hydroponic gardening method is probably a better method than the normal soil gardening method.  As you can see hydroponic gardening works.  Soil might be the old way to garden, but it still is a good way to grow plants.  Plants can grow in many different substances.  There are many types of plants that will work when trying to grow them hydroponically.  There are three main types of cultures in the hydroponic gardening method.  Hydroponic gardening has been around for years and still many people do not know that it exists.



Armstrong, Joseph. "Auxin,"  The World Book Encyclopedia. 1994.  Vol.1. Pp.988

Baker, Jerry. The World Book Encyclopedia.   1994. Vol.8.  Pp.37-39

Bridwell, Raymond. Hydroponic Gardening.  Santa Barbara, California Woodbridge Press Publishing Company, 1982. Pp. 79-86

Carlson, William H. "Hydroponics," The World Book Encyclopedia  1994. Vol. 9. Pp. 469-470

DiMichele, William A. The World Book Encyclopedia.  1994. Vol. 15.  Pp.536-539

Keating, Richard C. The World Book Encyclopedia 1994. Vol. 8.  Pp.173

Poincelot, Raymond P.  The World Book Encyclopedia. 1994. Vol. 2.  Pp. 474-475

Wagner, David H. ìPhotosynthesis,î  The World Book Encyclopedia. 1988. Vol. 15 Pp.434

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