What material do plants grow best in?

Jocelyn’s 2010 5th grade Science Fair was held today at school. For those of you wondering about various growing materials you might choose for radish seeds, we proudly share the entire project:

Purpose StatementDSC07331

I want to know what materials plants grow best in so I can grow successful plants on my own.

Hypothesis

I think the plants will grow best in the soil and sand because they are what people usually grow plants in.

Materials

  • 21 plastic cups
  • 3 cups potting soil
  • 3 cups sand
  • 3 cups rubber bands (cut up)
  • 3 cups woodchips
  • 3 cups unused nails
  • 3 cups shredded nails
  • 3 cups balled clay
  • An open box for the plastic cups
  • 1 ruler
  • A paper for writing down observations
  • Water
  • A partly sunlit area
  • 1 packet radish seeds

Procedure

  1. Fill each plastic cup with 1 cup of each material.
  2. Plant 1 radish seed in each plastic cup.
  3. Water each seed with ΒΌ cup water.
  4. Leave the cups in a partly sunlit area and observe daily. When the seeds sprout, measure them once each day with a ruler. After measuring each plant, water them all 1 tablespoon.

After two weeks, record the final growth and discover which material worked the best.

Results

The plants in the soil were most successful. The plants in the clay and nails didn’t grow at all. The other results are below.

Tallest Shortest

Soil 3 1/2 in 3 in

Sand 3 1/2 in 2 1/2 in

Woodchips 3 in 2 1/2 in

Rubber Bands 3/4 in did not grow

Styrofoam 3/4 in did not grow

Clay did not grow did not grow

Nails did not grow did not grow

Conclusion

I was right. The plants grew best in the soil and the sand. However, the woodchips were also very productive. As I suspected, the plants in the clay and the nails did not grow at all. The plants in the rubber bands and the styrofoam grew (but not very much), which surprised me. I started to do garbanzo beans too, but they got moldy so we had to throw them away. Maybe I will grow plants in woodchips or sand this spring!