I'm as much at fault, as it isn't all that obvious and the original
explanation was a bit ambiguous. Its just as well you posted a follow
up as well, as many people don't.

No problem... Its always worth posting a follow up - otherwise people
looking in the archives just hit a dead end...

What you're doing right now, might affect the plant for the next five
years or ten years i.e whether you spend five minutes or ten minutes
now, could have a big impact. (On the other hand you could just take
a chance and sling it in any old way not bothering about Ph and end
up with a bush burdened down with fruit - maybe all the cautions are
uneccesssary. )

So dig as wide a hole is is feasable, line the walls with plastic of some
kind, and that's about it.

snip

Good thing about making this mistake was that it was easy to dig up and
lift out the whole bag! I've cut the bottom off, lined the sides of the
hole (about 3' diameter - as big as the space would allow) using the
original plastic plus another piece and re-planted the blueberry (its a
northland by the way *). As you say, a ten minute job may well make all
the difference in a plant which should be there for many years.

I have a space next to it that would accommodate another - I'm very
tempted to buy a different variety for cross pollination. Crocus have
one that looks good... although maybe I should see how the first one
gets on - I dont want to overcrowd the patch in the first year !

* I don't have the time right now to research the drainage preferences
of blueberries. If it needs good drainage you might want to think of
incorporate some gravel at the bottom of the hole.( Or again you could
just sling it in. Wish you hadn't posted ?)

According to various sites, blueberries need to be kepy moist. I have
broken up the soil at the bottom of the hole, but not added any gravel.

Thanks again for the tips - I'm very pleased that I posted the question !


* PLANT DESCRIPTION
A cross between the lowbush and highbush blueberry, in midseason
'Northland' produces abundant sweet, bright-blue fruit with a wild
blueberry taste on plants that reach 3–4 feet. This extremely productive
cultivar's blooms withstand light frost. Blueberry foliage turns fiery
red in fall, giving it great ornamental value as well. I didn't know
this last point - should look god alongside my Jap maple!