primrose problem

A week before xmas i planted primroses/conifer in a container destined for an out door area. They seem to do well the first week but now seem to be dying. Last week i fed them with tomato feed, not sure if too early, but do not want them to die.

By contrast primroses in the garden centre are blooming. any advice appreciated

You may get some advice over on [broken link removed]

I think it's still too cold for vine weevils, but it might be worth checking through the soil.