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 herbs like basil, and lettuces like arugula, red salad bowl, buttercrunch, pak choi, and black seeded simpson.  For the full procedure to use with other crops, visit

Soak the rockwool in pH adjusted water

Soak the rockwool for 30 minutes in pH adjusted water. (5.5-7.0)

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. For a small amount of water ,like the apple juice container in the picture, use just a few ml of the pH – or pH + at a time to adjust the pH. Don’t stress out if you can’t get the pH exactly right.  Most plants will do fine if the pH is close.

After 30 minutes, drain the water from the container.


Pour some seeds into your hand

Pour some seeds into your hand


Drop 6-10 seeds into the hole.

Pour seeds on 3X5 cards for little students to plant

Pour seeds on 3X5 cards for little students to plant

Give each student a rockwool cube and pour out several seeds onto 3X5 cards.  The students can count out seeds and place them in the hole in the rockwool.

Add about 1/4″ of water to the bottom of the tray. You want the rockwool to stay damp until the next day.

Cover the container so that all the seeds are in the dark. (A file folder works well for this.) Place container on a counter or in a cabinet.

Check each morning and evening (or when school is out) for sprouts.  Replace the water each day. Most lettuce will only take two days to sprout.

When seeds have sprouted you’ll see white fuzz on the seeds.

It’s important to uncover the seeds when they sprout and place them on the Tower Garden base and turn on the lights.

Replace the water each day with 1/4 inch of water.

After about a week, seedlings should look like this and are ready to place in the Tower Garden

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.