@1Right_Angle, Yes realised this very late :-/ ... First thought i did some wetting misstake.
DUnno if white plasstic poits would be enough to prevent this... Probably go with some straw around the pot next year...
@1Right_Angle, Yes, i was going crazy why i get top yellow leaves... U can see on the soil pic that there is a stripe of wunderfull white roots. This is were i got my sticks round the pot to save them from wind... Sprayed some fish emulsion in the days after i found this... Dunno if it helped... But yellowing stopped after that and sunscreen.