Elephant Heart is slow to come into bearing for a Japanese type plum. If it has had few blossoms there's no reason to think pollination is a problem. E. H. should be quite compatible with Santa Rosa although it's been years since I've dealt with CA weather conditions.

I say, give the tree a couple more years and it will be a wonderful plum for you if it was correctly labeled.

My Santa Rosa is through blooming before my Elephant Heart blooms. If you have an overlap you should be OK. If your chill hours are borderline erratic blooming is often noted, in your case it may be an advantage. Al

Fruit Berry and Nut Inventory says it takes 500 hours of chilling so I guess you may be onto something if they are correct. They say Santa Rosa is an excellent pollinator for it as well.

For S. CA they recommend it for the inland areas only so I guess you may have to lose that one. If you bought it from a nursery nearby you certainly would appear to have a legitimate complaint although at this point a refund is as unlikely as it is inadequate.

As grown here in southeastern NY it definitely is a late bearer though.

I will give it one more year, but next year I will start to top work it if I do not get fruit

I live in northern ca and my elephant heart blooms before my santa rosa so it never pollinates but blooms profusely. I think I will buy an earlier blooming santa rosa as they bloom at different times and I may have a late blooming santa rosa the tag did not specify.

Petunia, trees can work as pollinators in one region and fail in another. The longer the growing season the more spread out is the bloom, with the least overlap between earlier and later bloomers. Here in southeastern NY the entire bloom period from apricot to last apples is only 2 or 3 weeks so varieties are more likely compatible.

To my knowledge, there is only one Santa Rosa clone. Any variance in flowering time is most likely mislabeling, IMO.

My Elephant Heart blooms later than Santa Rosa also, maybe it is because my Elephant Heart flowers after leafing, while my Santa Rosa seems to flower as it is leafing.

But is there an overlap? Here the two do have that.

Can a Flavor King Pluot cross pollinate the Elephant Heart?