With the greatest of respect to all concerned, most of what he says is complete myth, happenstance, coincidence and balderdash in my humble opinion.
And as for his assertion that this year the oak trees have provided acorns to feed the robins European robins are mainly insectiverous although they do eat small seeds. I'm not aware of them eating acorns - I'd have thought acorns are much too big for them.
Last winter was one of the hardest for many years and many small birds (and large ones too, such as barn owls) were lost, and yet Mr King says that last year 'Nature decided' that the robins didn't need the acorns I'm sorry but that's complete poppycock.
He may be confused - American robins, a different species to ours, eat acorns - perhaps he's prophesying the weather for the USA?
I hope he didn't use similar techniques when trying to solve crimes, rather than relying on established scientific and forensic methods.
As for the plants mentioned above, none of those need special treatment to see them through any British winter, so just give the soil around them a good mulching to enrich the soil and improve it's structure and water retentiion. The plants will be fine.