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.

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.

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.

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.


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.