Standards (Microsoft Word Document)

Materials:

• Containers
• Plants
• Different types of growing media such as various commercial potting soil mixes, garden soil, compost, sand, peat moss
• Garden journal

• Ask students to list the different elements plants need to grow? (light, air, water, nutrients and a place to grow)
• What is soil? Why do plants need soil? Do all plants grow in the same type of soil?
• What about container plants? Do you think they need the same type of soil as those growing in the ground? What might be different about the growing conditions in containers?
• Ask students to hypothesize what they think will happen if container plants are not happy with the soil mix they are growing in. Write down their predictions. How can they test their hypotheses?

Exploration

1. Fill container gardens using a variety of growing media. You can either make your own mix using different amounts of ingredients such as garden soil, compost, sand, and peat moss or you can buy different types of commercial soil mixes to compare. Make sure to use identical containers to reduce variables that can affect the outcome.

2. Plant identical plant varieties in the different soil mixes. Include plants that have high water needs (most flowering annuals and vegetables) and some that have low water needs (most perennials and natives). If supplies allow, have more than one container for each mix to increase scientific accuracy.

3. Provide each container with the same amount of water, light, and nutrients. Record weekly observations of plant growth in garden journals. Ask students to pay special attention to plant height and details of plant appearance.

4. Organize data into a chart or graph. Discuss your results. Did the results support your hypotheses? Did all the plants grow the same in each of the soil mixes? What do your results say about the importance of proper growing media for container gardens?

Making Connections

Branching Out

• Engage students in math activities related to your container gardens. For instance, they can estimate the volume of soil mix needed for a specific container based on its dimensions, then check their math by filling the container. You can also explore the concepts and interrelationships of volume, weight, and density.
• Focus on soil by growing a food crop harvested from the soil such as potatoes (other options include beets, carrots, radishes, sweet potatoes and turnips). You can grow a lot of potatoes in a small space by stacking the soil as the plant grows, as described below.
  
  A Stack of Potatoes
  Find a well-drained container that's at least 30 inches deep, such as a barrel, trash can, or stack of tires. Put in about a foot of moist soil, compost, or soil mix and lay potato seed pieces, cut sides down, on top. As the potatoes sprout and grow, students should mulch the shoots with more soil mix, sawdust, or straw. Have your keen observers try to figure out where the potatoes will form. (They form above the original "seed piece.") It's important to keep the tubers covered, because if they are exposed to the sun, they may turn green, which indicates the presence of toxic solanine. When the foliage turns brown, dig in or turn the barrel on its side and pour out the contents.

  An alternate method is to fill one tire with growing media, plant the potato pieces and cover them with a few inches of soil or straw. As soon as the green sprouts are six inches above the tire rim, add another tire and fill it half full of soil mix or straw. Continue adding tires and covering potatoes in this manner through the growing season.