You see the plant you’ve been looking for growing lustily in a big pot in a nursery sales bed. You pay the 5-litre premium, you take it home, dig the hole, add the fertilizer, knock the plant out of the pot – and a meagre little root comes out in a cascade of fresh compost.
It happened to me again yesterday. The guilty nursery was Wisley. There should be a decent delay after repotting for plants to fill their pots again before they are offered for sale.