Patience. It may take 6-8 years to blossom. How big was it when planted?

tj

It also may depend on the type of flowering cherry and where you live. An extended cold period with several nights at freezing or below just before the bloom period can destroy the flowers. Since flowering cherries are some of the earliest ornamentals to bloom, this is more common than not in some locations.

"over two years ago"

It sounds like it's having a rough adjustment period if they're not growing after some years. I don't see your locale, so this is going to be heavily dependent, but since others have these and they're common, it's certainly not an area where these trees have issues. I'm starting by simply assuming the tree is just slow to adjust and wants to be fed.

Next spring, when things are warm and the tree is leafed out, try giving it a feed about the same time you'd feed the lawn (around Memorial Day in the US, or May 25th if you're not in the US) at the same rate you'd feed the lawn; the equivalent of 1 pound of nitrogen per thousand square feet. Make absolutely certain to use something high in nitrogen, but without any herbicides in it (those would harm the tree). If it's also high in phosphorus and potassium (the second and third numbers), I have no objection, but you may or may not require that. Only a soil test would be able to tell for certain.

You can continue that every 4 to 6 weeks through the season, stopping in September (in most locales) to assure new growth has time to harden off before winter. You want at least six weeks before frost/freeze for new growth to harden.

If it's not budding, it could be that it's just not happy yet and still adjusting.

Even if and when frost nicked, they're still relatively pretty, so it's nothing much to be concerned overmuch about. It's more the stalled state and the fact that you don't report any buds that I'm worried about.

And fortunately, even here in Pennsylvania (the late frost/freeze capital of the planet, I sometimes think), late extended frosts don't seem to impact the blossoms too terribly much. Source: the three the neighbor has that he and I work on as a joint venture since he knows...well, nothing about plants. They still do fine even in very early April weather that was 75 followed by 25 and ice for their blooming period, even if they're not precisely thrilled with it!

But that's not the problem you're reporting anyway. First, let's see if we can get some growth going. Blooming will come along with that.