I have discovered why my new Correa rootlings were not growing as they should. Other plants which like alkaline conditions were just sittting also, despite the warm weather we had. My potting mix is not the pH it should be. It is way too acid at pH 5.5. It was only after hearing the tale of woe of another grower that the ‘penny dropped’ and I realised that my problem was probably the same. A pH test on the offending mix proved that it was the same problem, although not as low as his was. He thought that Azaelias would have done excellently in his mix.
Solution? Keith watered his pots with lime water made with a teapoon of lime in a standard watering can. He had to do this four times altogether before the pH was an acceptable 6. I have had to do the same. I have also added a cupful of lime to a wheelbarrow load of the potting mix for new seedlings and cuttings. It goes against the grain to do this when the soil pH is 9+! However if it solves the problem in the potting mix and I get the growth on the plants then it is worth it. It has been so disappointing to see the losses and the unthrifty new plants. I was certainly thankful to be alerted to a new scenario for my nursery.