Cherry rootstock question

I have a rootstock in bloom from a sour cherry that died . small light pink flowers . Any ideas which one it is . I guess a pic would help . Has bloomed before but no fruit that I recall . It is out of the way spot .

S

So they start out blushed pink and open to white . Tree is 6-7 feet tall .

The most common rootstocks for sour cherry are mahaleb and mazzard. There are other rootstocks but it’s unlikely that’s what you have unless the original tree was mail ordered from a specialty nursery. Of the two rootstocks I think the greatest likelyhood is that your rootstock is mahaleb since that is the most common of the two.

I know both of those . It was a Danube sour and came from West coast nursery that sells to commercial orchards . Vanwell maybe . I found a older post of mine from 2017 . Seems it may be Gisela 6 . It was probably on the tag . I had 3 and none lived very long . I did backup one on Mahaleb and still have it . Very disappointed in it so far .

Mahaleb is a good rootstock for sandy loam or sandy soil. It does poorly in heavy soils like clay. So if it is struggling it maybe a soil issue.

Not struggling . Blooms like crazy but most fruitlets drop . A few make it to ripe . It is said to improve production with age . Many have complained about this trait . I think Montmorency is tops .