Materials
Procedure
 Using the scissors, cut off the spout side of each milk carton.
- On the opposite side, use the scissors to punch three or four small holes for drainage.
- Using the marker, label each carton A, B, C, or D.
- Fill each carton about two-thirds full of soil.
- In carton A, use your finger to poke holes in the soil about 3 centimeters (cm) deep and 8 cm apart.
- Place a bean in each hole, and it cover gently with soil.
- Repeat steps 4-6 with the remaining cartons, setting holes as specified below.
- Carton B: 3 cm deep and 5 cm apart
- Carton C: 3 cm deep and 3 cm apart
- Carton D: 3 cm deep and 1 cm apart
- Place the cartons on a large tray, and put the tray in a sunny place.
- Water the soil carefully. Use a spray bottle to help keep from disturbing the beans. The soil should be moist but not soaking wet.
- Observe the cartons daily, and record your observations in your science journal.
- Once the plants begin to sprout, choose three plants from each carton, and measure their height each day. Record this data in your science journal.
- At the end of a set time period, such as 2 weeks, take an average height of the plants in each carton. Use this information to create a graph.
- Answer the following questions about your plants’ growth.
- Did the seeds sprout at the same time? Why or why not?
- Did the seedlings grow at the same rate? Why or why not?
- Did the seedlings grow better in some cartons that in others? Why or why not?
- Using what you have learned in this activity, explain why gardeners have to “thin out” seedlings.
- What effect would weeds have on a garden?
- Why would NASA researchers need to find the best spacing for plants in a garden that could be used on the Space Station to provide oxygen?
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