Step 1: Get supplies and print worksheets.

Each student will need:

• a Grass Head worksheet — print it here
• a ruler
• a ballpoint pen or Sharpie (water-soluble markers will not work)
• a popsicle stick
• 3 small rubber bands
• 2 paper towels
• a paper plate
• a nylon kneesock, cut as described below (Available in boxes of 10 pairs at drugstores and on Amazon. Ten pairs is enough for 40 students.)

In addition, you will need:

• about 2 cups (about one pound) of fast-sprouting grass seeds — check your hardware store for something like this from Home Depot or this from Amazon.
• bowls to hold ¼ cup of grass seed (one bowl for each group of 4 students)
• cups of water (one cup for each group of 4 students)
• a few ceramic coffee mugs and four plates (styrofoam, plastic, or ceramic) for the grass heads while they are sprouting. (Plates must have raised edges so they’ll hold water.)

Step 2: Before class, complete final preparations.

This step takes about 15 minutes.

Cut the stockings in half and tie the open ends as shown in this video.

Label two plates “Face Up” and two plates “Face Down.”

Step 3: After class — maintenance

The paper towel of the grass head will soak up water and keep the seeds wet — but only if part of paper towel stays wet. Make sure to keep a water supply in each plate and cup so your grass heads stay wet. Grass heads can soak up lots of water.

Your class will examine your grass heads during the next mystery. You’ll talk about whether students’ predictions were right and will find a surprise. For more on that, see Mystery 4: Should you water a cactus?