had to have a look in the book
it says robinia (false acacia)
is not fussy and grows in any soil type.flowers appear in june.
oh dear
your tree is not looking too promising if still no leaves.
hang on a while though and see what happens,some garden centres do give refunds if its died for no apparent reason.

If you mean Robinea pseudo-acacia Frisia which is the most commonly sold form of this tree, then there has been a mass death of these up and down the country. Talking to a Council Tree officer the other day and he was saying that he has been called out to look at dozens in his area alone. They did not like the winter at all. Ours is definitely dead.

these might be different trees the spelling in my book was different to yours.not sure on this one.

My typing gets worse. Robinia pseudoacacia Frisia is correct name.