There can be adverse effects related to soil sterilisation so a little research was required to make sure that only the beneficial effects were transferred into the growing routines. For instance, experiments have proved that lime added after sterilisation is far more beneficial than when added before, similarly superphosphate is added after sterilisation to counter the retarding effect of excessive ammonia produced during the steaming process. This is now a new annual task for me following good results during the 1998 season. I decided to change my compost mix to something a little stronger. As I mentioned on the Just Starting page, propagation is carried out using soilless compost with perlite added to the mix.
Subsequent stages make use of the sterilised materials described above.
20 litres sterilised previous years potting mix 20 litres fresh peat Coarse grit added until the mix feels right, typically between 5 and 10 litres.