Basic Seed Starting Procedure for Schools

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.

The Plants in My Tower Garden are Wilting

Not enough (or too much) water to the plants

  1. Check that the pump timer is set to 15 minutes on, 45 minutes off. (indoor growing)
  2. Check pH (should be between 5.5 and 6.5)
  3. Check that rockwool is pushed all the way to the bottom of the netpot.
  4. Check that holes at the top aren’t clogged.
  5. Run pump while top is open and check that water is going all the way to the top.
    If not…
    Check that the Tower Garden sections are firmly seated.
    Clean the pump (See instructions to clean the pump.)
    Pull blue hose that connects the pump to the Tower Garden and run water through it. Clean if clogged.

If everything checks out with the water, then you might have insects on your plants in the Tower Garden.

Insects and Diseases on the Tower Garden


The best way is to keep insects off your plants is to practice good Tower Garden hygiene.

  1. Don’t have plants in regular soil near your Tower Garden.
  2. Between plantings,
    • Clean netpots thoroughly and soak them in a 10/1 solution of hot water and vinegar for 30 minutes.
    • Use a wet rag to clean the inside of the pots.
  3. Keep the side of the Tower Garden clean.
  4. If you start seedlings on the Tower Garden base, replace the water daily. (Follow this seed starting procedure.)
    If you do get insects,try these ideas.  If these ideas don’t work, you’re better off pulling the plants, cleaning the Tower Garden from top to bottom, and replanting.


The best way to keep diseases from your plants is to practice good Tower Garden hygiene.

If you follow the above precautions for insects, it will be rare that you have diseases on your plants – especially if you’re growing indoors.  If you do find something on the leaves that you don’t expect, here’s a great article to help.

Weekly Maintenance of the Tower Garden

The weekly maintenance for indoor growing is usually very consistent  The water level drops about the same amount each week.

A regular outdoor watering can works well as it takes about 1 watering can per week to refill the green tub.  Don’t use softened water or very hard water.


Once the water is added, measure out 50 ml of Tower Tonic A and 50 ml of Tower Tonic B for every full watering can poured into the Tower Garden. Add the Tower Tonic separately.  (Don’t mix them)



Use the pH test kit to test the pH of the water in the green tub. Put 5 ml of water from the Tower Garden into the vial. Drip 5 drops of the solution into the vial and compare the color with the test strip. The pH should be within 5.5 and 6.5.  Use about 10 ml of the pH Up or pH Down as needed to bring the pH to the correct number. (Further Instructions come with the test kit.)


Tower Garden Setup

Here are videos from the Tower Garden company to help you setup your Tower Garden for the first time.

This video covers adding water, nutrient solution, and setting the timer.

Since I mostly grow indoors, I use a 2 gallon watering can instead of a garden hose. The video will tell you to set the timer at 15 minutes on, 15 minutes off. For indoor growing, this should be 15 minutes on, 45 minutes off because the rockwool won’t dry out as much indoors as it will outdoors.