Posted: 07/01/2013 at 14:19
You can use garden soil riddled then into a micro wave or into a bucket and boiling water poured on it to sterilise the soil.
Drain the water and dry out then mix with washed sand and you have a perfect seed mix, I also add some fine grit for drainage.
When doing a lot of trays use riddled potting compost with washed sand and fine grit, one third of each although for some seed I use only a quarter compost, most seed will germinate in damp sand, when I spilt some tomato seed on my hot sand bed I had better results than from the actual seed trays.
As a lad we did not have bespoke compost so it was all done with soil, we had no problems with that so why do otherwise?