Slow growing in raised beds

The end of last summer we filled some raised beds in a recently constructed greenhouse with ‘premium’ compost from a bulk landscape supplier HALS in Hobart. The problem is everything we’ve planted grows very slowly or not at all. Tried the following to try and find the issue:

  • Added all purpose pelleted plant fertiliser
  • mixed in blood and bone and rock dust
  • open windows during the day to maintain good circulation and temp extremes
  • checked soil pH which was around 7
  • water regularly and periodically and add Seasol and Charley carp.

Has anyone got and ideas what the issue might be?