Think I may. Have an Ivanovka plum tree that is showing plums that are Most definitely Not ivanovka. (blue/purple)
Our ivanovka’s were ripe and harvested at least 2 wks ago, these are a good week minimum from ripe, they’re still hard.
I should also note the same tree’s ivanovka plums were ripe a couple weeks ago. (and very tasty)
Plums are still rock hard, and while somewhat greenish are showing a Very Red blush, not like fofonoff blush, real Red. More the colour of Lee Red or a cherry.
To give more info, 2 yrs ago I seeded the orchard to white clover. Flowers nonstop, and if you sit anywhere it’s just, bzzzzz from the wild bees. Within about 40 yds there’s a wide variety of plums, cherry plums, plumcots, apples, apricots.
Crosses wouldn’t effect this year’s fruitn only fruit from the seed would change the next year. So if the plum isnt the right color what you have is a mislabel(most likely) or a chance mutation
Do you mean that you have real Ivanovka plums and inferior tasting plums from the same tree? If it is from a different branch it could be rootstock plums. Alternatively, it could be plum pox virus that can causes the tasteless, hard plums.
It could be a “sport”,which is when the tree’s genes change to another variant,a spontaneous mutation.Sometimes only one branch is affected.
It’s how the Broken Heart plum came to be.
Rootstock suckering would be my first thought too. If the branch is coming from below the graft union it would explain both the different variety and the later ripening. Worth checking where exactly on the tree those branches originate.