seed planting and propagation
seedling propagation
how to make a styrofoam seedling propagation box
The easiest way to grow seedlings is with a styrofoam seedling propagation box.  This page explains how to make your own styrofoam seedling box.

Photo of styrofoam hot boxStyrofoam seedling propagation box with three millimetre sheet of glass on top.
Materials required

  • Styrofoam box
    In Australia these can usually supermarkets and green grocers for nothing
  • Newspaper
  • Compost or good quality soil
  • Potting or seedling Mix
    You will only need a small amount
  • Sheet of cut glass 48 x 35 cm (approximately 19 x 14 inches)





setting up a styrofoam propagation box


Cover the bottom of the box with three or four sheets of newspaper.


Fill the bottom2/3 thirds of the box with well rotted compost or good quality garden soil then top up with a thin layer of seedling or potting mix.


With your hand press five or six furrows across the seedling/potting mix.


Label the seeds so you know what you have planted.
1.  Cover the bottom of the box with newspaper
Cover the bottom of the box with three or four sheets of newspaper, making sure that all the holes in the bottom are covered.  As the holes are quite large much of the soil will fall through if you do not cover them with paper.

2.  Fill  the box with compost or soil
Fill the bottom 2/3 thirds of the box with well rotted compost or good quality garden soil.  you can add some sheep or cow manure if you like.

3.  Cover the top with seedling mix
Cover the top with 2cm (3/4 inch) of commercial seedling or potting mix, leaving about 5 to 6 cm (2 to 2/12 inches) clear from the top of the box.

I have used both seedling and potting mix with success.  The main difference being that putting mix is a lot cheaper.   Alternatively you can make your own seed raising mix.

4.  Press furrows across the seedling mix.
With your hand press five or six furrows across the seedling/potting mix.  I usually use five and make the first furrow in the centre, which makes it easier to space them evenly.  The furrows should be around one centimetre (1/3 inch) deep.


5.  Sprinkle seeds in the rows, cover and label.
Sprinkle the seeds you want to plant along the furrows then with your thumb and  forefinger pinch the seedling mix back across the rows.  Alternatively you can simply add a fine layer of seedling/potting mix on the rows.

Finally label the seeds so you know what you have planted and water in with a weak solution of liquid fertiliser.   In early Spring cover with a sheet of cut glass or plastic, otherwise just leave open.

As a styrofoam boxes are quite large when fully planted out they can produce a lot of seedlings, so it's best to plant one or two rows at a time. That way the seedlings will be staggered over a period of weeks.