Hello, why are my michelias yellowing and dropping leaves in autumn? 

Hi Jan, 

They have probably dried out at some stage over the summer. Mulch around them to help conserve soil moisture, and regularly feed in early spring and again in late summer with an acid based fertiliser such as Tui Acid Food or Tui Enrich Rose, Camellia, Azalea & Gardenia Controlled Release Fertiliser for plants that enjoy acid soil conditions. 

Thanks, Tui Team.