This seed starting procedure has been adapted for the classroom from a procedure shared by Joe of It’s a little different than what’s in the Tower Garden manual, but works well in a classroom. This procedure works best growing basil, arugula, red salad bowl, buttercrunch, pak choi, and black seeded simpson.  For the full procedure to use with other crops, visit

  1. Make up a 32 oz bottle of pH adjusted water.  (Do NOT use softened water) The pH should be between 5.5 and 6.5.  Use the pH test kit that comes with the Tower Garden. Put 5 ml of water in the vlal and add 5 drops of the solution.  Compare the color with the colored dots on the test paper. Use just 10 ml of the pH – or pH + at a time to adjust the pH. See the directions on the pH test kit to test the water.
  2. Soak rockwool cubes in the pH adjusted water for 30 minutes.
  3. Shake excess water from the rockwool cubes.  (Don’t squeeze)
  4. Place rockwool cubes into the tray that came with the Tower Garden.  If you want to keep track of which student plants what seeds, use empty butter (or similar) containers.
  5. Drop 6-10 seeds into the hole.  (It’s OK if some seeds land on top.)
  6. Pour about ¼” of pH adjusted water into the bottom of the empty container.  (You’ll probably need to mix up more pH adjusted water.)
  7. Cover container with construction paper and place in the warmest place in the room.
  8. Check next day for sprouts and replace water in the container with pH adjusted water.
  9. After just a couple of days, you should see white ‘fuzz’ around the seeds.  The white fuzz means they’ve sprouted. (See picture below.) Uncover the container and place it on the base of the Tower Garden and turn on the lights.  Each day replace water in container with pH adjusted water.
  10. If you started the seeds on Monday or Tuesday, by the next week, you should be able to place the seedlings in the Tower Garden.
  11. Fill the Tower Garden green tub with water up to 3 inches from the top (about 20 gallons).. For new seedlings, add 200 ml of Tower Tonic ’A’ and 200 ml of Tower Tonic ‘B’.  Balance the pH.

When you see white fuzz on the seeds, it’s time to put them on the Tower Garden base with the lights turned on.

This basic procedure will produce fairly good lettuce for classroom use.  If you’d like to grow better plants, visit  for a more involved process.