OS6 Burying Seeds

Directions on seed packets usually tell how much dirt to put over the seeds. Some gardeners say to only plant a seed as deep as it is tall. Is this important? Let’s find out.

 

Question: Does it matter how deep a seed is buried?

materials needed

Materials:

10 pumpkin seeds

5-16 oz. planting cups

potting soil

metric ruler

plastic wrap

 

Procedure:

Step 1: Open your science journal. Write the date and Investigation 6. Copy Table 1 into your journal.

Step 2: Number the cups 1 to 5. Mark each cup with a little line at 4cm, 6.5cm, 9cm, 11.5cm and 14cm from the bottom.

Step 3: Put 4cm potting soil in each cup. Be sure this is pushed down firmly and still 4cm deep. If you hold the cup up with a light behind it, you can see the dirt is level with your first mark.

Step 4: Lay two seeds on the dirt in Cup 1

Step 5: Put 2.5cm potting soil in each cup to the 6.5cm mark, pushing it down firmly

planting pumpkin seeds

Each cup must be labeled. Each layer of soil is added and one cup is planted until all are done.

Step 6: Lay two seeds on the dirt in Cup 2

Step 7: Put 2.5cm potting soil in each cup to the 9cm mark, pushing it down firmly

Step 8: Lay 2 seeds on the dirt in Cup 3

Step 9: Put 2.5cm potting soil in each cup to the 11.5cm mark, pushing it down firmly

Step 10: Lay 2 seeds on the dirt in Cup 4

Step 11: Put 2.5cm potting soil in each cup to the 14cm mark, pushing it down firmly

Step 12: Lay two seeds on the dirt in Cup 5

Step 13: Add water to all the cups so the soil is damp but not soggy. Cover the tops with plastic wrap. Set the cups in a warm place.

pumpkin sprout

A hook and cotyledons is pushing up out of the soil of the cup.

Step 14: Check the cups every day for pumpkin sprouts. Take the plastic wrap off when the sprouts appear.

Step 15: Count seven days after the first seeds germinate or when the seeds planted the deepest appear, carefully dump each cup out and look at the seeds.

 

Observations:

 

seeds on top of soil

The radicle must push down into the soil to start the pumpkin root. Exposed on the surface it can dry out before it gets into the moist soil.

Describe the sprouts when you take them out of the cups:

 

seedlings in cups

The seeds are trying to grow in the various cups labeled 1 to 5.

Conclusions:

What is the best depth to plant the pumpkin seeds? Why do you pick this depth?

 

Can seeds be buried too deep to grow? Why do you think this?

pumpkin seedlings

Taken out of the cups the seedlings are arranged from top of the soil on the left to the deepest on the right.

 

Does the size of the seeds matter? Why do you think so?